| Description | Gene-cellular compartment co-occurrence scores from text-mining biomedical abstracts |
| Measurement | association by text-mining |
| Association | protein-cellular component associations from automated text-mining of biomedical literature |
| Category | structural or functional annotations |
| Resource | COMPARTMENTS |
| Citation(s) | |
| Last Updated | 2025 Apr 28 |
| Stats |
|
| API | |
| Script | |
| Downloads |
Gene Attribute
Gene Similarity
Attribute Similarity
UMAP
3170 sets of proteins co-occuring with cellular components in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset.
| Gene Set | Description |
|---|---|
| Inhibin B complex | Heterodimeric hormone composed of an inhibin alpha subunit complexed with an inhibin beta-B subunit. |
| Organelle | Organized structure of distinctive morphology and function. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton, and prokaryotic structures such as anammoxosomes and pirellulosomes. Excludes the plasma membrane. |
| Plasma lipoprotein particle | A spherical particle with a hydrophobic core of triglycerides and/or cholesterol esters, surrounded by an amphipathic monolayer of phospholipids, cholesterol and apolipoproteins. Plasma lipoprotein particles transport lipids, which are non-covalently associated with the particles, in the blood or lymph. |
| low-density lipoprotein particle | A lipoprotein particle, rich in cholesterol esters and low in triglycerides that is typically composed of APOB100 and APOE and has a density of 1.02-1.06 g/ml and a diameter of between 20-25 nm. LDL particles are formed from VLDL particles (via IDL) by the loss of triglyceride and gain of cholesterol ester. They transport endogenous cholesterol (and to some extent triglycerides) from peripheral tissues back to the liver. |
| Transcription factor AP-1 complex | |
| Cellular anatomical entity | |
| Nucleus | A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent. |
| TORC1 complex | A protein complex that contains at least TOR (target of rapamycin) and Raptor (regulatory-associated protein of TOR), or orthologs of, in complex with other signaling components. Mediates the phosphorylation and activation of S6K. In Saccharomyces, the complex contains Kog1p, Lst8p, Tco89p, and either Tor1p or Tor2p. |
| Intracellular organelle | Organized structure of distinctive morphology and function, occurring within the cell. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton. Excludes the plasma membrane. |
| Intracellular anatomical structure | |
| Pituitary gonadotropin complex | |
| cellular_component | The part of a cell or its extracellular environment in which a gene product is located. A gene product may be located in one or more parts of a cell and its location may be as specific as a particular macromolecular complex, that is, a stable, persistent association of macromolecules that function together. |
| high-density lipoprotein particle | A lipoprotein particle with a high density (typically 1.063-1.21 g/ml) and a diameter of 5-10 nm that contains APOAs and may contain APOCs and APOE; found in blood and carries lipids from body tissues to the liver as part of the reverse cholesterol transport process. |
| NF-kappaB complex | A protein complex that consists of a homo- or heterodimer of members of a family of structurally related proteins that contain a conserved N-terminal region called the Rel homology domain (RHD). In the nucleus, NF-kappaB complexes act as transcription factors. In unstimulated cells, NF-kappaB dimers are sequestered in the cytoplasm by IkappaB monomers; signals that induce NF-kappaB activity cause degradation of IkappaB, allowing NF-kappaB dimers to translocate to the nucleus and induce gene expression. |
| TORC2 complex | A protein complex that contains at least TOR (target of rapamycin) and Rictor (rapamycin-insensitive companion of TOR), or orthologs of, in complex with other signaling components. Mediates the phosphorylation and activation of PKB (also called AKT). In Saccharomyces, the complex contains Avo1p, Avo2p, Tsc11p, Lst8p, Bit61p, Slm1p, Slm2p, and Tor2p. |
| Lewy body | Cytoplasmic, spherical inclusion commonly found in damaged neurons, and composed of abnormally phosphorylated, neurofilament proteins aggregated with ubiquitin and alpha-synuclein. |
| Cell periphery | The part of a cell encompassing the cell cortex, the plasma membrane, and any external encapsulating structures. |
| Apical junction complex | A functional unit located near the cell apex at the points of contact between epithelial cells, which in vertebrates is composed of the tight junction, the zonula adherens, and desmosomes and in some invertebrates, such as Drosophila, is composed of the subapical complex (SAC), the zonula adherens and the septate junction. Functions in the regulation of cell polarity, tissue integrity and intercellular adhesion and permeability. |
| Bicellular tight junction | |
| Cell junction | A cellular component that forms a specialized region of connection between two cells or between a cell and the extracellular matrix. At a cell junction, anchoring proteins extend through the plasma membrane to link cytoskeletal proteins in one cell to cytoskeletal proteins in neighboring cells or to proteins in the extracellular matrix. |
| Anchoring junction | A cell junction that mechanically attaches a cell (and its cytoskeleton) to neighboring cells or to the extracellular matrix. |
| cell-cell junction | A cell junction that forms a connection between two cells; excludes direct cytoplasmic junctions such as ring canals. |
| Tight junction | An occluding cell-cell junction that is composed of a branching network of sealing strands that completely encircles the apical end of each cell in an epithelial sheet; the outer leaflets of the two interacting plasma membranes are seen to be tightly apposed where sealing strands are present. Each sealing strand is composed of a long row of transmembrane adhesion proteins embedded in each of the two interacting plasma membranes. |
| Intracellular membrane-bounded organelle | Organized structure of distinctive morphology and function, bounded by a single or double lipid bilayer membrane and occurring within the cell. Includes the nucleus, mitochondria, plastids, vacuoles, and vesicles. Excludes the plasma membrane. |
| Membrane | Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins. |
| Type III intermediate filament | A type of intermediate filament, typically made up of one or more of the proteins vimentin, desmin, glial fibrillary acidic protein (GFAP), and peripherin. Unlike the keratins, the type III proteins can form both homo- and heteropolymeric IF filaments. |
| Intermediate filament | A cytoskeletal structure that forms a distinct elongated structure, characteristically 10 nm in diameter, that occurs in the cytoplasm of eukaryotic cells. Intermediate filaments form a fibrous system, composed of chemically heterogeneous subunits and involved in mechanically integrating the various components of the cytoplasmic space. Intermediate filaments may be divided into five chemically distinct classes: Type I, acidic keratins; Type II, basic keratins; Type III, including desmin, vimentin and others; Type IV, neurofilaments and related filaments; and Type V, lamins. |
| AMPA glutamate receptor complex | |
| Intermediate filament cytoskeleton | Cytoskeletal structure made from intermediate filaments, typically organized in the cytosol as an extended system that stretches from the nuclear envelope to the plasma membrane. Some intermediate filaments run parallel to the cell surface, while others traverse the cytosol; together they form an internal framework that helps support the shape and resilience of the cell. |
| Polymeric cytoskeletal fiber | |
| membrane-bounded organelle | Organized structure of distinctive morphology and function, bounded by a single or double lipid bilayer membrane. Includes the nucleus, mitochondria, plastids, vacuoles, and vesicles. Excludes the plasma membrane. |
| protein-containing complex | |
| Sarcoplasmic reticulum | A fine reticular network of membrane-limited elements that pervades the sarcoplasm of a muscle cell; continuous over large portions of the cell and with the nuclear envelope; that part of the endoplasmic reticulum specialized for calcium release, uptake and storage. |
| VEGF-A complex | |
| Sarcoplasm | The cytoplasm of a muscle cell; includes the sarcoplasmic reticulum. |
| interleukin-12 complex | A protein complex that is composed of an interleukin-12 alpha (p35, product of the IL12A gene) and an interleukin-12 beta subunit (p40, product of the IL12B gene) and is secreted into the extracellular space. |
| Hemoglobin complex | An iron-containing, oxygen carrying complex. In vertebrates it is made up of two pairs of associated globin polypeptide chains, each chain carrying a noncovalently bound heme prosthetic group. |
| Bcl-2 family protein complex | A protein complex that consists of members of the Bcl-2 family of anti- and proapoptotic regulators. Bcl-2 proteins respond to cues from various forms of intracellular stress, such as DNA damage or cytokine deprivation, and interact with opposing family members to determine whether or not the caspase proteolytic cascade should be unleashed. |
| Cytoplasm | All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. |
| Mitochondrion | A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration. |
| non-membrane-bounded organelle | Organized structure of distinctive morphology and function, not bounded by a lipid bilayer membrane. Includes ribosomes, the cytoskeleton and chromosomes. |
| Chromosome | A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information. |
| MutSalpha complex | A heterodimer involved in the recognition and repair of base-base and small insertion/deletion mismatches. In human the complex consists of two subunits, MSH2 and MSH6. |
| DNA repair complex | A protein complex involved in DNA repair processes including direct reversal, base excision repair, nucleotide excision repair, photoreactivation, bypass, double-strand break repair pathway, and mismatch repair pathway. |
| Extracellular space | That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid. |
| Cytosol | The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes. |
| Extracellular region | The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite. |
| BAK complex | An oligomeric protein complex consisting of BAK, a member of the Bcl-2 family of anti- and proapoptotic regulators. |
| Immunoglobulin complex | A protein complex that in its canonical form is composed of two identical immunoglobulin heavy chains and two identical immunoglobulin light chains, held together by disulfide bonds and sometimes complexed with additional proteins. An immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Mitochondrial envelope | The double lipid bilayer enclosing the mitochondrion and separating its contents from the cell cytoplasm; includes the intermembrane space. |
| ISGF3 complex | |
| triglyceride-rich plasma lipoprotein particle | |
| very-low-density lipoprotein particle | A triglyceride-rich lipoprotein particle that is typically composed of APOB100, APOE and APOCs and has a density of about 1.006 g/ml and a diameter of between 20-80 nm. It is found in blood and transports endogenous products (newly synthesized cholesterol and triglycerides) from the liver. |
| serotonin-activated cation-selective channel complex | |
| Origin recognition complex | A multisubunit complex that is located at the replication origins of a chromosome. |
| DNA-dependent protein kinase complex | A protein complex that is involved in the repair of DNA double-strand breaks and, in mammals, V(D)J recombination events. It consists of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and the DNA end-binding heterodimer Ku. |
| Autophagosome | |
| IgM immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and in its circulating form complexed with J chain in polymeric forms. An IgM immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Endoplasmic reticulum protein-containing complex | |
| External encapsulating structure | A structure that lies outside the plasma membrane and surrounds the entire cell. |
| Extracellular matrix | A structure lying external to one or more cells, which provides structural support for cells or tissues; may be completely external to the cell (as in animals and bacteria) or be part of the cell (as in plants). |
| Inflammasome complex | |
| Ionotropic glutamate receptor complex | A multimeric assembly of four or five subunits which form a structure with an extracellular N-terminus and a large loop that together form the ligand binding domain. The C-terminus is intracellular. The ionotropic glutamate receptor complex itself acts as a ligand-gated ion channel; on binding glutamate, charged ions pass through a channel in the center of the receptor complex. |
| Inhibin complex | Heterodimeric hormone composed of an inhibin alpha subunit complexed with either an inhibin beta-A subunit, to form inhibin A, or an inhibin beta-B subunit, to form inhibin B. |
| RNAi effector complex | Any protein complex that mediates the effects of small interfering RNAs on gene expression. Most known examples contain one or more members of the Argonaute family of proteins. |
| Intracellular non-membrane-bounded organelle | Organized structure of distinctive morphology and function, not bounded by a lipid bilayer membrane and occurring within the cell. Includes ribosomes, the cytoskeleton and chromosomes. |
| RISC complex | A ribonucleoprotein complex that contains members of the Argonaute family of proteins, small interfering RNAs (siRNAs) or microRNAs (miRNAs), and miRNA or siRNA-complementary mRNAs, in addition to a number of accessory factors. The RISC complex is involved in posttranscriptional repression of gene expression through downregulation of translation or induction of mRNA degradation. |
| DNA ligase IV complex | A eukaryotically conserved protein complex that contains DNA ligase IV and is involved in DNA repair by non-homologous end joining; in addition to the ligase, the complex also contains XRCC4 or a homolog, e.g. Saccharomyces Lif1p. |
| Molybdopterin cofactor (Moco) biosynthesis adenylyltransferase complex | |
| Eukaryotic translation initiation factor 4F complex | The eukaryotic translation initiation factor 4F complex is composed of eIF4E, eIF4A and eIF4G; it is involved in the recognition of the mRNA cap, ATP-dependent unwinding of the 5'-terminal secondary structure and recruitment of the mRNA to the ribosome. |
| Mycolate outer membrane | A mycolic acid-rich cell outer membrane containing a lipid bilayer and long-chain mycolic acids (hydroxylated branched-chain fatty acids) that are covalently linked to the cell wall peptidoglycan via an arabinogalactan network. Found in mycobacteria and related genera (e.g. corynebacteria). |
| Glucose transporter complex | |
| P-TEFb complex | |
| carboxy-terminal domain protein kinase complex | A protein complex that phosphorylates amino acid residues of RNA polymerase II C-terminal domain repeats; phosphorylation occurs mainly on Ser2 and Ser5. |
| cyclin/CDK positive transcription elongation factor complex | |
| Hemidesmosome | A cell-substrate junction that forms a point of contact between the basal surface of epithelial cells and the basal lamina. Morphologically resembles desmosomes; attached to intermediate filaments. |
| GINS complex | A heterotetrameric protein complex that associates with replication origins, where it is required for the initiation of DNA replication, and with replication forks. |
| anaphase-promoting complex | A ubiquitin ligase complex that degrades mitotic cyclins and anaphase inhibitory protein, thereby triggering sister chromatid separation and exit from mitosis. Substrate recognition by APC occurs through degradation signals, the most common of which is termed the Dbox degradation motif, originally discovered in cyclin B. |
| Shelterin complex | |
| Nuclear telomere cap complex | A complex of DNA and protein located at the end of a linear chromosome in the nucleus that protects and stabilizes a linear chromosome. |
| Telomere cap complex | A complex of DNA and protein located at the end of a linear chromosome that protects and stabilizes a linear chromosome. |
| chromosome, telomeric repeat region | |
| Phosphatase complex | A protein complex which is capable of phosphatase activity. |
| Phosphatidylinositol phosphate phosphatase complex | |
| PTEN phosphatase complex | |
| DNA replication preinitiation complex | A protein-DNA complex assembled at eukaryotic DNA replication origins immediately prior to the initiation of DNA replication. The preinitiation complex is formed by the assembly of additional proteins onto an existing prereplicative complex. In budding yeast, the additional proteins include Cdc45p, Sld2p, Sld3p, Dpb11p, DNA polymerases, and others; in fission yeast the GINS complex is present. |
| Interferon regulatory factor 5 complex | |
| Cell surface | The external part of the cell wall and/or plasma membrane. |
| MutSbeta complex | A heterodimer involved in binding to and correcting insertion/deletion mutations. In human the complex consists of two subunits, MSH2 and MSH3. |
| NLRP3 inflammasome complex | A protein complex that consists of three components, NLRP3 (NALP3), PYCARD and caspase-1. It is activated upon exposure to whole pathogens, as well as a number of structurally diverse pathogen- and danger-associated molecular patterns (PAMPs and DAMPs) and environmental irritants. Whole pathogens demonstrated to activate the NLRP3 inflammasome complex include the fungi Candida albicans and Saccharomyces cerevisiae, bacteria that produce pore-forming toxins, including Listeria monocytogenes and Staphylococcus aureus, and viruses such as Sendai virus, adenovirus, and influenza virus. |
| Endoribonuclease complex | A protein complex which is capable of endoribonuclease activity. |
| Slit diaphragm | A specialized cell-cell junction found between the interdigitating foot processes of the glomerular epithelium (the podocytes) in the vertebrate kidney, which is adapted for facilitating glomerular filtration. |
| Extracellular exosome | |
| Extracellular membrane-bounded organelle | Organized structure of distinctive morphology and function, bounded by a lipid bilayer membrane and occurring outside the cell. |
| Extracellular vesicle | Any vesicle that is part of the extracellular region. |
| ESC/E(Z) complex | A multimeric protein complex that can methylate lysine-27 and lysine-9 residues of histone H3. In Drosophila the core subunits of the complex include ESC, E(Z), CAF1 (NURF-55) and SU(Z)12. In mammals the core subunits of the complex include EED, EZH2, SUZ12 and RBBP4. |
| NADPH oxidase complex | A enzyme complex of which the core is a heterodimer composed of a light (alpha) and heavy (beta) chain, and requires several other water-soluble proteins of cytosolic origin for activity. Functions in superoxide generation by the NADPH-dependent reduction of O2. |
| Apoptosome | A multisubunit protein complex involved in the signaling phase of the apoptotic process. In mammals it is typically composed of seven Apaf-1 subunits bound to cytochrome c and caspase-9. A similar complex to promote apoptosis is formed from homologous gene products in other eukaryotic organisms. |
| Mre11 complex | Trimeric protein complex that possesses endonuclease activity; involved in meiotic recombination, DNA repair and checkpoint signaling. In Saccharomyces cerevisiae, the complex comprises Mre11p, Rad50p, and Xrs2p; complexes identified in other species generally contain proteins orthologous to the Saccharomyces cerevisiae proteins. |
| IgE immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of the IgE isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgE immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Chromatin | The ordered and organized complex of DNA, protein, and sometimes RNA, that forms the chromosome. |
| Neuron to neuron synapse | |
| Cohesin complex | A protein complex that is required for sister chromatid cohesion in eukaryotes. The cohesin complex forms a molecular ring complex, and is composed of structural maintenance of chromosomes (SMC) and kleisin proteins. For example, in yeast, the complex is composed of the SMC proteins Smc1p and Smc3p, and the kleisin protein Scc1p. In vertebrates, the complex is composed of the SMC1 (SMC1A or SMC1B) and SMC3 heterodimer attached via their hinge domains to a kleisin (RAD21, REC8 or RAD21L) which links them, and one STAG protein (STAG1, STAG2 or STAG3). |
| Cytoplasmic vesicle membrane | The lipid bilayer surrounding a cytoplasmic vesicle. |
| STING complex | |
| Caveola | A membrane raft that forms small pit, depression, or invagination that communicates with the outside of a cell and extends inward, indenting the cytoplasm and the cell membrane. Examples include any of the minute pits or incuppings of the cell membrane formed during pinocytosis. Such caveolae may be pinched off to form free vesicles within the cytoplasm. |
| Plasma membrane raft | A membrane raft that is part of the plasma membrane. |
| Elastic fiber | An extracellular matrix part that consists of an insoluble core of polymerized tropoelastin monomers and a surrounding mantle of microfibrils. Elastic fibers provide elasticity and recoiling to tissues and organs, and maintain structural integrity against mechanical strain. |
| Asymmetric synapse | A type of synapse occurring between an axon and a dendritic spine or dendritic shaft. Asymmetric synapses, the most abundant synapse type in the central nervous system, involve axons that contain predominantly spherical vesicles and contain a thickened postsynaptic density. |
| Early endosome | A membrane-bounded organelle that receives incoming material from primary endocytic vesicles that have been generated by clathrin-dependent and clathrin-independent endocytosis; vesicles fuse with the early endosome to deliver cargo for sorting into recycling or degradation pathways. |
| Vesicle membrane | The lipid bilayer surrounding any membrane-bounded vesicle in the cell. |
| Ire1 complex | A type-I transmembrane protein complex located in the endoplasmic reticulum which forms in response to the accumulation of unfolded protein in the ER and evokes the unfolded protein response (UPR) by splicing the mRNA encoding master transcriptional regulators of the UPR, Hac. It cleaves a single phosphodiester bond in each of two RNA hairpins (with non-specific base paired stems and loops of consensus sequence CNCNNGN, where N is any base) to remove an intervening intron from the target transcript. Its catalytic activity depends on its conformation as a dimer and oligomer. |
| gamma-secretase complex | A protein complex that has aspartic-type endopeptidase activity, and contains a catalytic subunit, presenilin (PS), that is a prototypical member of the GxGD-type aspartyl peptidases. The complex also contains additional subunits, including nicastrin, APH-1, PEN-2, and a regulatory subunit, CD147. Gamma-secretase cleaves several transmembrane proteins including the cell surface receptor Notch and the beta-amyloid precursor protein. |
| Postsynapse | |
| Postsynaptic specialization | |
| SCF ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul1 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by a Skp1 adaptor and an F-box protein. SCF complexes are involved in targeting proteins for degradation by the proteasome. The best characterized complexes are those from yeast and mammals (with core subunits named Cdc53/Cul1, Rbx1/Hrt1/Roc1). |
| Microbody | Cytoplasmic organelles, spherical or oval in shape, that are bounded by a single membrane and contain oxidative enzymes, especially those utilizing hydrogen peroxide (H2O2). |
| Plasma membrane protein complex | |
| Myofibril | The contractile element of skeletal and cardiac muscle; a long, highly organized bundle of actin, myosin, and other proteins that contracts by a sliding filament mechanism. |
| interleukin-23 complex | A protein complex that is composed of an interleukin-23 alpha (p19, product of the IL23A gene) and an interleukin-12 beta (p40, product of the IL12B gene) subunit and is secreted into the extracellular space. |
| Troponin complex | A complex of accessory proteins (typically troponin T, troponin I and troponin C) found associated with actin in muscle thin filaments; involved in calcium regulation of muscle contraction. |
| Striated muscle thin filament | Filaments formed of actin and associated proteins; attached to Z discs at either end of sarcomeres in myofibrils. |
| Myofilament | Any of the smallest contractile units of a myofibril (striated muscle fiber). |
| Sarcomere | The repeating unit of a myofibril in a muscle cell, composed of an array of overlapping thick and thin filaments between two adjacent Z discs. |
| Contractile fiber | Fibers, composed of actin, myosin, and associated proteins, found in cells of smooth or striated muscle. |
| Peroxisome | A small organelle enclosed by a single membrane, and found in most eukaryotic cells. Contains peroxidases and other enzymes involved in a variety of metabolic processes including free radical detoxification, lipid catabolism and biosynthesis, and hydrogen peroxide metabolism. |
| PcG protein complex | A chromatin-associated multiprotein complex containing Polycomb Group proteins. In Drosophila, Polycomb group proteins are involved in the long-term maintenance of gene repression, and PcG protein complexes associate with Polycomb group response elements (PREs) in target genes to regulate higher-order chromatin structure. |
| TSC1-TSC2 complex | A protein complex consisting of at least tumerin and hamartin; its formation may regulate hamartin homomultimer formation. The complex acts as a GTPase activating protein (GAP) for the small GTPase (Rheb), and inhibits the TOR signaling pathway. |
| SMN complex | A protein complex that contains the survival motor neuron (SMN) protein and at least eight additional integral components, including the Gemin2-8 and Unrip proteins; the complex is found in the cytoplasm and in nuclear Gems, and is involved in spliceosomal snRNP assembly in the cytoplasm and in pre-mRNA splicing in the nucleus. |
| SMN-Sm protein complex | A protein complex formed by the association of several methylated Sm proteins with the SMN complex; the latter contains the survival motor neuron (SMN) protein and at least eight additional integral components, including the Gemin2-8 and unrip proteins; additional proteins, including galectin-1 and galectin-3, are also found in the SMN-SM complex. The SMN-Sm complex is involved in spliceosomal snRNP assembly in the cytoplasm. |
| Sm-like protein family complex | |
| Ferritin complex | A protein complex that binds iron and acts as a major iron storage system. Intracellular and extracellular ferritin complexes have different ratios of two types of ferritin monomer, the L (light) chain and H (heavy) chain. |
| Endopeptidase Clp complex | A protein complex comprised of members of the ClpX, ClpC, ClpD, ClpP or ClpR protein families. ClpPs are the proteolytic subunit of active complexes, and ClpA and ClpX form the regulatory subunits. Enzymatically active and inactive complexes can form. |
| SWI/SNF complex | A SWI/SNF-type complex that contains nine or more proteins, including both conserved (core) and nonconserved components; the Swi2/Snf2 ATPase is one of the core components. |
| GCH1 complex | |
| insulin-like growth factor binding protein complex | A complex of proteins which includes the insulin-like growth factor (IGF) and a number of IGF-binding proteins. The complex plays a role in growth and development. |
| Organelle membrane | A membrane that is one of the two lipid bilayers of an organelle envelope or the outermost membrane of single membrane bound organelle. |
| Organelle envelope | A double membrane structure enclosing an organelle, including two lipid bilayers and the region between them. In some cases, an organelle envelope may have more than two membranes. |
| Mitochondrial membrane | Either of the lipid bilayers that surround the mitochondrion and form the mitochondrial envelope. |
| Filtration diaphragm | A specialized cell-cell junction found between the cells of the excretory system, which provides a barrier for filtration of blood or hemolymph. |
| serine-type endopeptidase complex | |
| Cul4-RING E3 ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul4 family and a RING domain protein form the catalytic core; substrate specificity is conferred by an adaptor protein. |
| Cul4A-RING E3 ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul4A subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by an adaptor protein. |
| cullin-RING ubiquitin ligase complex | Any ubiquitin ligase complex in which the catalytic core consists of a member of the cullin family and a RING domain protein; the core is associated with one or more additional proteins that confer substrate specificity. |
| Small nuclear ribonucleoprotein complex | A complex composed of RNA of the small nuclear RNA (snRNA) class and protein, found in the nucleus of a eukaryotic cell. These are typically named after the snRNA(s) they contain, e.g. U1 snRNP or U4/U6 snRNP. Many, but not all, of these complexes are involved in splicing of nuclear mRNAs. |
| Postsynaptic density | The postsynaptic density is a region that lies adjacent to the cytoplasmic face of the postsynaptic membrane at excitatory synapse. It forms a disc that consists of a range of proteins with different functions, some of which contact the cytoplasmic domains of ion channels in the postsynaptic membrane. The proteins making up the disc include receptors, and structural proteins linked to the actin cytoskeleton. They also include signalling machinery, such as protein kinases and phosphatases. The postsynaptic density may be part of a neuron or a muscle cell or a glial cell. |
| Microfibril | Extracellular matrix components occurring independently or along with elastin. Thought to have force-bearing functions in tendon. In addition to fibrillins, microfibrils may contain other associated proteins. |
| serine-type peptidase complex | |
| Supramolecular complex | |
| Supramolecular polymer | |
| Supramolecular fiber | |
| Cytoskeleton | Any of the various filamentous elements that form the internal framework of cells, and typically remain after treatment of the cells with mild detergent to remove membrane constituents and soluble components of the cytoplasm. The term embraces intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles. |
| Actin cytoskeleton | The part of the cytoskeleton (the internal framework of a cell) composed of actin and associated proteins. Includes actin cytoskeleton-associated complexes. |
| Gap junction | A cell-cell junction that is composed of an array of small channels that permit small molecules to pass from one cell to another. At gap junctions, the membranes of two adjacent cells are separated by a uniform narrow gap of about 2-4 nm that is spanned by channel-forming proteins called connexins, which form hexagonal tubes called connexons. |
| Endoplasmic reticulum | The irregular network of unit membranes, visible only by electron microscopy, that occurs in the cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached). |
| mRNA editing complex | A protein complex that posttranscriptionally catalyzes insertion, deletion or substitution of nucleotides at multiple sites within nascent mRNA transcripts to produce mature mRNAs in eukaryotes. |
| Cardiac Troponin complex | |
| Nascent polypeptide-associated complex | A heterodimeric protein complex that can reversibly bind to ribosomes, and is located in direct proximity to newly synthesized polypeptide chains as they emerge from the ribosome. |
| RNA N6-methyladenosine methyltransferase complex | |
| Ribonucleoprotein complex | A macromolecular complex containing both protein and RNA molecules. |
| Atg1/ULK1 kinase complex | |
| Extracellular ferritin complex | A ferritin complex located in the extracellular region. Extracellular ferritin complexes contain L (light) chains but few or no H (heavy) chains. |
| Membrane raft | Any of the small (10-200 nm), heterogeneous, highly dynamic, sterol- and sphingolipid-enriched membrane domains that compartmentalize cellular processes. Small rafts can sometimes be stabilized to form larger platforms through protein-protein and protein-lipid interactions. |
| Membrane microdomain | |
| Endoplasmic reticulum membrane | The lipid bilayer surrounding the endoplasmic reticulum. |
| Endoplasmic reticulum subcompartment | |
| Plasma membrane | The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins. |
| Nuclear outer membrane-endoplasmic reticulum membrane network | The continuous network of membranes encompassing the nuclear outer membrane and the endoplasmic reticulum membrane. |
| Extracellular organelle | Organized structure of distinctive morphology and function, occurring outside the cell. Includes, for example, extracellular membrane vesicles (EMVs) and the cellulosomes of anaerobic bacteria and fungi. |
| Recycling endosome | Organelle consisting of networks of 60nm tubules organized around the microtubule organizing centre in some cell types. They transport molecules (e.g., receptors, transporters, lipids) derived from endosomes, the Golgi apparatus, or the cytoplasm to the plasma membrane. Transported molecules may be recycled for reuse, or may be newly synthesized. |
| Vacuole | A closed structure, found only in eukaryotic cells, that is completely surrounded by unit membrane and contains liquid material. Cells contain one or several vacuoles, that may have different functions from each other. Vacuoles have a diverse array of functions. They can act as a storage organelle for nutrients or waste products, as a degradative compartment, as a cost-effective way of increasing cell size, and as a homeostatic regulator controlling both turgor pressure and pH of the cytosol. |
| Nuclear cyclin-dependent protein kinase holoenzyme complex | Cyclin-dependent protein kinase (CDK) complex found in the nucleus. |
| Phosphomannomutase complex | |
| Integrin alpha4-beta7 complex | An integrin complex that comprises one alpha4 subunit and one beta7 subunit. |
| Intramolecular phosphotransferase complex | |
| DNA packaging complex | A protein complex that plays a role in the process of DNA packaging. |
| Arp2/3 protein complex | A stable protein complex that contains two actin-related proteins, Arp2 and Arp3, and five novel proteins (ARPC1-5), and functions in the nucleation of branched actin filaments. |
| Growth factor complex | A protein complex that has growth factor activity. |
| RecQ family helicase-topoisomerase III complex | |
| dystrophin-associated glycoprotein complex | A multiprotein complex that forms a strong mechanical link between the cytoskeleton and extracellular matrix; typical of, but not confined to, muscle cells. The complex is composed of transmembrane, cytoplasmic, and extracellular proteins, including dystrophin, sarcoglycans, dystroglycan, dystrobrevins, syntrophins, sarcospan, caveolin-3, and NO synthase. |
| Myosin filament | A protein complex containing myosin heavy chains, plus associated light chains and other proteins, in which the myosin heavy chains are arranged into a filament. |
| Membrane attack complex | A protein complex produced by sequentially activated components of the complement cascade inserted into a target cell membrane and forming a pore leading to cell lysis via ion and water flow. |
| Neurofilament | A type of intermediate filament found in the core of neuronal axons. Neurofilaments are heteropolymers composed of three type IV polypeptides: NF-L, NF-M, and NF-H (for low, middle, and high molecular weight). Neurofilaments are responsible for the radial growth of an axon and determine axonal diameter. |
| Spliceosomal snRNP complex | A ribonucleoprotein complex involved in formation of the spliceosome and composed of one or more snRNA and multiple protein components. |
| IkappaB kinase complex | A trimeric protein complex that phosphorylates inhibitory-kappaB (I-kappaB) proteins. The complex is composed of two kinase subunits (alpha and beta) and a regulatory gamma subunit (also called NEMO). In a resting state, NF-kappaB dimers are bound to inhibitory IKB proteins, sequestering NF-kappaB in the cytoplasm. Phosphorylation of I-kappaB targets I-kappaB for ubiquitination and proteasomal degradation, thus releasing the NF-kappaB dimers, which can translocate to the nucleus to bind DNA and regulate transcription. |
| LUBAC complex | A ubiquitin ligase complex that catalyzes linear head-to-tail polyubiquitin conjugation on its targets. In human the complex consists of RBCK1, RNF31 and SHARPIN, and has an MW of approximately 600 kDa, suggesting a heteromultimeric assembly of its subunits. LUBAC stands for Linear Ubiquitin Chain Assembly Complex. |
| SWI/SNF superfamily-type complex | A protein complex that contains an ortholog of the Saccharomyces ATPase Swi2/Snf2 as one of the core components and mediates assembly of nucleosomes, changes to the spacing or structure of nucleosomes, or some combination of those activities in a manner that requires ATP. |
| Paranode region of axon | An axon part that is located adjacent to the nodes of Ranvier and surrounded by lateral loop portions of myelin sheath. |
| Microprocessor complex | A protein complex that binds to heme and to pri-miRNAs, and is required for the formation of a pre-microRNA (pre-miRNA), the initial step of microRNA (miRNA) biogenesis. The complex is composed of the double-stranded-RNA-specific RNase Drosha (also called RNASEN) and the RNA-binding protein DGCR8 (heme-free or heme-bound forms). Within the complex, DGCR8 function as a molecular anchor necessary for the recognition of pri-miRNA at dsRNA-ssRNA junction and directs RNASEN/Drosha to cleave the 3' and 5' strands of a stem-loop to release hairpin-shaped pre-miRNAs. |
| Nkx-2.5 complex | |
| IgG immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of an IgG isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgG immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| collagen-containing extracellular matrix | |
| Lysosome | A small lytic vacuole that has cell cycle-independent morphology and is found in most animal cells and that contains a variety of hydrolases, most of which have their maximal activities in the pH range 5-6. The contained enzymes display latency if properly isolated. About 40 different lysosomal hydrolases are known and lysosomes have a great variety of morphologies and functions. |
| ATPase complex | |
| Ripoptosome | A protein complex whose core components are the receptor-interacting serine/threonine-protein kinases RIPK1 and RIPK3 (also called RIP1 and RIP3). Formation of the ripoptosome can induce an extrinsic apoptotic signaling pathway or a necroptotic signaling pathway. The composition of this protein complex may depend on several factors including nature of the signal, cell type and more. |
| Ribonuclease III complex | A protein complex which is capable of ribonuclease III activity. |
| Thrombospondin complex | |
| Lytic vacuole | A vacuole that is maintained at an acidic pH and which contains degradative enzymes, including a wide variety of acid hydrolases. |
| Efflux pump complex | |
| Neuron projection | A prolongation or process extending from a nerve cell, e.g. an axon or dendrite. |
| MutLalpha complex | A heterodimer involved in the recognition of base-base and small insertion/deletion mismatches. In human the complex consists of two subunits, MLH1 and PMS2. |
| chromosome, centromeric region | The region of a chromosome that includes the centromeric DNA and associated proteins. In monocentric chromosomes, this region corresponds to a single area of the chromosome, whereas in holocentric chromosomes, it is evenly distributed along the chromosome. |
| Synapse | The junction between a nerve fiber of one neuron and another neuron or muscle fiber or glial cell; the site of interneuronal communication. As the nerve fiber approaches the synapse it enlarges into a specialized structure, the presynaptic nerve ending, which contains mitochondria and synaptic vesicles. At the tip of the nerve ending is the presynaptic membrane; facing it, and separated from it by a minute cleft (the synaptic cleft) is a specialized area of membrane on the receiving cell, known as the postsynaptic membrane. In response to the arrival of nerve impulses, the presynaptic nerve ending secretes molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane. |
| Actomyosin | Any complex of actin, myosin, and accessory proteins. |
| C/EBP complex | |
| Glutathione hydrolase complex | |
| Inclusion body | A discrete intracellular part formed of aggregated molecules such as proteins or other biopolymers. |
| Mitochondrial inner membrane peptidase complex | Protease complex of the mitochondrial inner membrane, consisting of at least two subunits, involved in processing of both nuclear- and mitochondrially-encoded proteins targeted to the intermembrane space. |
| Organelle subcompartment | A compartment that consists of a lumen and an enclosing membrane, and is part of an organelle. |
| CMG complex | A protein complex that contains the GINS complex, Cdc45p, and the heterohexameric MCM complex, and that is involved in unwinding DNA during replication. |
| intermediate-density lipoprotein particle | A triglyceride-rich lipoprotein particle that typically contains APOB100, APOE and APOCs and has a density of 1.006-1.019 g/ml and a diameter of between 25-30 nm. IDL particles are found in blood and are formed by the delipidation of very-low-density lipoprotein particles (VLDL). IDL particles are removed from blood by the liver, following binding to the APOE receptor, or are converted to low-density lipoprotein (LDL). |
| Retromer complex | A conserved multimeric membrane-associated complex involved in retrograde transport from endosomes to the Golgi apparatus. For example, the budding yeast retromer comprises Vps35p, Vps29p, Vps26p, Vps5p, and Vps17p. |
| Neurotransmitter receptor complex | |
| chromosome, telomeric region | The terminal region of a linear chromosome that includes the telomeric DNA repeats and associated proteins. |
| pre-replicative complex | A protein-DNA complex that forms at the origin of replication during the initial step of DNA replication and allows the origin to become competent, or 'licensed', for replication. |
| Focal adhesion | Small region on the surface of a cell that anchors the cell to the extracellular matrix and that forms a point of termination of actin filaments. |
| Cytoplasmic stress granule | A dense aggregation in the cytosol composed of proteins and RNAs that appear when the cell is under stress. |
| cell-substrate junction | A cell junction that forms a connection between a cell and the extracellular matrix. |
| Oxidoreductase complex | Any protein complex that possesses oxidoreductase activity. |
| Chylomicron | A large lipoprotein particle (diameter 75-1200 nm) composed of a central core of triglycerides and cholesterol surrounded by a protein-phospholipid coating. The proteins include one molecule of apolipoprotein B-48 and may include a variety of apolipoproteins, including APOAs, APOCs and APOE. Chylomicrons are found in blood or lymph and carry lipids from the intestines into other body tissues. |
| Endoplasmic reticulum chaperone complex | A protein complex that is located in the endoplasmic reticulum and is composed of chaperone proteins, including BiP, GRP94; CaBP1, protein disulfide isomerase (PDI), ERdj3, cyclophilin B, ERp72, GRP170, UDP-glucosyltransferase, and SDF2-L1. |
| Synaptonemal complex | A proteinaceous scaffold found between homologous chromosomes during meiosis. |
| core-binding factor complex | |
| Mucus layer | An extracellular region part that consists of a protective layer of mucus secreted by epithelial cells lining tubular organs of the body such as the colon or secreted into fluids such as saliva. Mucus is a viscous slimy secretion consisting of mucins (i.e. highly glycosylated mucin proteins) and various inorganic salts dissolved in water, with suspended epithelial cells and leukocytes. |
| Dystroglycan complex | A protein complex that includes alpha- and beta-dystroglycan, which are alternative products of the same gene; the laminin-binding component of the dystrophin-associated glycoprotein complex, providing a link between the subsarcolemmal cytoskeleton (in muscle cells) and the extracellular matrix. Alpha-dystroglycan is an extracellular protein binding to alpha-laminin and to beta-dystroglycan; beta-dystroglycan is a transmembrane protein which binds alpha-dystroglycan and dystrophin. |
| C-fiber | The axon of a dorsal root ganglion cell that are responsive to pain and temperature. C-fibers are small in diameter (0.2-1.5 um) and unmyelinated. |
| Synaptonemal structure | |
| Transcription factor TFIIA complex | A component of the transcription machinery of RNA Polymerase II. In humans, TFIIA is a heterotrimer composed of an alpha (P35), beta (P19) and gamma subunits (P12). |
| Plasma membrane region | A membrane that is a (regional) part of the plasma membrane. |
| Integrin alpha4-beta1 complex | An integrin complex that comprises one alpha4 subunit and one beta1 subunit. |
| Intrinsic component of plasma membrane | The component of the plasma membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor), which spans or is embedded in one or both leaflets of the membrane. |
| Integral component of plasma membrane | The component of the plasma membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Neuromuscular junction | The junction between the axon of a motor neuron and a muscle fiber. In response to the arrival of action potentials, the presynaptic button releases molecules of neurotransmitters into the synaptic cleft. These diffuse across the cleft and transmit the signal to the postsynaptic membrane of the muscle fiber, leading to a change in post-synaptic potential. |
| Transcription factor TFIIF complex | A general transcription initiation factor which in humans consists of a heterodimer of an alpha and a beta subunit. Helps recruit RNA polymerase II to the initiation complex and promotes translation elongation. |
| T cell receptor complex | A protein complex that contains a disulfide-linked heterodimer of T cell receptor (TCR) chains, which are members of the immunoglobulin superfamily, and mediates antigen recognition, ultimately resulting in T cell activation. The TCR heterodimer is associated with the CD3 complex, which consists of the nonpolymorphic polypeptides gamma, delta, epsilon, zeta, and, in some cases, eta (an RNA splice variant of zeta) or Fc epsilon chains. |
| Fanconi anaemia nuclear complex | A protein complex composed of the Fanconi anaemia (FA) proteins including A, C, E, G and F (FANCA-F). Functions in the activation of the downstream protein FANCD2 by monoubiquitylation, and is essential for protection against chromosome breakage. |
| Nucleoplasm | That part of the nuclear content other than the chromosomes or the nucleolus. |
| IgA immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of the IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and sometimes complexed with J chain or J chain and secretory component. An IgA immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Dendritic lamellar body | A specialized secretory organelle found in neurons and associated with the formation of dendrodendritic gap junctions. |
| Aryl hydrocarbon receptor complex | A protein complex that acts as an aryl hydrocarbon (Ah) receptor. Cytosolic and nuclear Ah receptor complexes have different subunit composition, but both contain the ligand-binding subunit AhR. |
| beta-catenin destruction complex | A cytoplasmic protein complex containing glycogen synthase kinase-3-beta (GSK-3-beta), the adenomatous polyposis coli protein (APC), and the scaffolding protein axin, among others; phosphorylates beta-catenin, targets it for degradation by the proteasome. |
| Actin filament | A filamentous structure formed of a two-stranded helical polymer of the protein actin and associated proteins. Actin filaments are a major component of the contractile apparatus of skeletal muscle and the microfilaments of the cytoskeleton of eukaryotic cells. The filaments, comprising polymerized globular actin molecules, appear as flexible structures with a diameter of 5-9 nm. They are organized into a variety of linear bundles, two-dimensional networks, and three dimensional gels. In the cytoskeleton they are most highly concentrated in the cortex of the cell just beneath the plasma membrane. |
| Plasma membrane signaling receptor complex | |
| Endomembrane system | A collection of membranous structures involved in transport within the cell. The main components of the endomembrane system are endoplasmic reticulum, Golgi bodies, vesicles, cell membrane and nuclear envelope. Members of the endomembrane system pass materials through each other or though the use of vesicles. |
| Cell outer membrane | A lipid bilayer that forms the outermost membrane of the cell envelope; enriched in polysaccharide and protein; the outer leaflet of the membrane contains specific lipopolysaccharide structures. |
| Vesicle | Any small, fluid-filled, spherical organelle enclosed by membrane or protein. |
| Plasma membrane bounded cell projection | |
| Exocyst | A protein complex peripherally associated with the plasma membrane that determines where vesicles dock and fuse. At least eight complex components are conserved between yeast and mammals. |
| Apolipoprotein B mRNA editing enzyme complex | Protein complex that mediates editing of the mRNA encoding apolipoprotein B; catalyzes the deamination of C to U (residue 6666 in the human mRNA). Contains a catalytic subunit, APOBEC-1, and other proteins (e.g. human ASP; rat ASP and KSRP). |
| Epsilon DNA polymerase complex | A heterotetrameric DNA polymerase complex that catalyzes processive DNA synthesis in the absence of PCNA, but is further stimulated in the presence of PCNA. The complex contains a large catalytic subunit and three small subunits, and is best characterized in Saccharomyces, in which the subunits are named Pol2p, Dpb2p, Dpb3p, and Dpb4p. Some evidence suggests that DNA polymerase epsilon is the leading strand polymerase; it is also involved in nucleotide-excision repair and mismatch repair. |
| Cell projection | A prolongation or process extending from a cell, e.g. a flagellum or axon. |
| Activin responsive factor complex | A transcriptionally active complex that binds to an activin response element (ARE) in the promoter of target genes, and is composed of two SMAD2 proteins, one SMAD4 protein and a Forkhead activin signal transducer (FAST) transcription factor. |
| HslUV protease complex | A protein complex that possesses ATP-dependent protease activity; consists of an ATPase large subunit with homology to other ClpX family ATPases and a peptidase small subunit related to the proteasomal beta-subunits of eukaryotes. In the E. coli complex, a double ring-shaped homohexamer of HslV is capped on each side by a ring-shaped HslU homohexamer. |
| Photosynthetic membrane | A membrane enriched in complexes formed of reaction centers, accessory pigments and electron carriers, in which photosynthetic reactions take place. |
| Peroxisomal matrix | The volume contained within the membranes of a peroxisome; in many cells the matrix contains a crystalloid core largely composed of urate oxidase. |
| AIM2 inflammasome complex | A protein complex that consists of AIM2, ASC, and caspase-1. AIM2 is a member of the HN-200 protein family that appears to be the sensor of cytosolic double-stranded DNA. |
| Interferon regulatory factor 7 complex | |
| Inhibitory synapse | A synapse in which an action potential in the presynaptic cell reduces the probability of an action potential occurring in the postsynaptic cell. |
| Brahma complex | A SWI/SNF-type complex that contains the ATPase product of the Drosophila brahma gene, or an ortholog thereof. |
| EmrE multidrug transporter complex | |
| Microbody lumen | The volume enclosed by the membranes of a microbody. |
| Photosystem II | A photosystem that contains a pheophytin-quinone reaction center with associated accessory pigments and electron carriers. In cyanobacteria and chloroplasts, in the presence of light, PSII functions as a water-plastoquinone oxidoreductase, transferring electrons from water to plastoquinone, whereas other photosynthetic bacteria carry out anoxygenic photosynthesis and oxidize other compounds to re-reduce the photoreaction center. |
| Cytoplasmic vesicle | A vesicle formed of membrane or protein, found in the cytoplasm of a cell. |
| Respiratory chain complex II | A part of the respiratory chain, containing the four polypeptide subunits of succinate dehydrogenase, flavin-adenine dinucleotide and iron-sulfur. Catalyzes the oxidation of succinate by ubiquinone. Connects the TCA cycle with the respiratory chain. |
| Interferon regulatory factor complex | A protein complex that consists of two interferon regulatory proteins (IRFs); may be homodimeric or heterodimeric. The activation of a latent closed conformation of IRF in the cytoplasm is triggered by phosphorylation of Ser/Thr residues in a C-terminal region. Phosphorylation stimulates the C-terminal autoinhibitory domain to attain a highly extended conformation triggering dimerization through extensive contacts to a second subunit. |
| Intracellular vesicle | |
| Calpain complex | |
| Succinate dehydrogenase complex | A multimeric complex which consists of flavoprotein (subunit A ; InterPro:IPR003952), iron-sulfur protein (subunit B) and membrane-bound cytochrome b560 (subunit C; InterPro:IPR000701). In some Archaea, the membrane-bound subunits (C or C and D) do not necessarily contain heme. Membrane-bound subunits can bind or react with quinones. |
| Cytoplasmic ribonucleoprotein granule | A ribonucleoprotein granule located in the cytoplasm. |
| Ndc80 complex | A protein complex conserved among eukaryotes that forms part of the kinetochore and plays an essential role in forming stable kinetochore-microtubule attachments. The complex contains proteins known in several species, including budding and fission yeasts, as Ndc80p, Nuf2p, Spc24p, and Spc25p. In vertebrates it is part of the outer plate of the kinetochore. |
| Cajal body | A class of nuclear body, first seen after silver staining by Ramon y Cajal in 1903, enriched in small nuclear ribonucleoproteins, and certain general RNA polymerase II transcription factors; ultrastructurally, they appear as a tangle of coiled, electron-dense threads roughly 0.5 micrometers in diameter; involved in aspects of snRNP biogenesis; the protein coilin serves as a marker for Cajal bodies. Some argue that Cajal bodies are the sites for preassembly of transcriptosomes, unitary particles involved in transcription and processing of RNA. |
| death-inducing signaling complex | A protein complex formed by the association of signaling proteins with a death receptor upon ligand binding. The complex includes procaspases and death domain-containing proteins in addition to the ligand-bound receptor, and may control the activation of caspases 8 and 10. |
| CGRP receptor complex | |
| RNA polymerase I complex | |
| Thylakoid | A membranous cellular structure that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the plasma membrane. In eukaryotes they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation. |
| FACT complex | An abundant nuclear complex, which was originally identified in mammalian systems as a factor required for transcription elongation on chromatin templates. The FACT complex has been shown to destablilize the interaction between the H2A/H2B dimer and the H3/H4 tetramer of the nucleosome, thus reorganizing the structure of the nucleosome. In this way, the FACT complex may play a role in DNA replication and other processes that traverse the chromatin, as well as in transcription elongation. FACT is composed of two proteins that are evolutionarily conserved in all eukaryotes and homologous to mammalian Spt16 and SSRP1. In metazoans, the SSRP1 homolog contains an HMG domain; however in fungi and protists, it does not. For example, in S. cerevisiae the Pob3 protein is homologous to SSRP1, but lacks the HMG chromatin binding domain. Instead, the yFACT complex of Spt16p and Pob3p, binds to nucleosomes where multiple copies of the HMG-domain containing protein Nhp6p have already bound, but Nhp6p does not form a stable complex with the Spt16p/Pob3p heterodimer. |
| Ribonucleoprotein granule | A non-membranous macromolecular complex containing proteins and translationally silenced mRNAs. RNA granules contain proteins that control the localization, stability, and translation of their RNA cargo. Different types of RNA granules (RGs) exist, depending on the cell type and cellular conditions. |
| Intrinsic component of membrane | The component of a membrane consisting of the gene products having some covalently attached portion, for example part of a peptide sequence or some other covalently attached group such as a GPI anchor, which spans or is embedded in one or both leaflets of the membrane. |
| Lewy neurite | Elongated neuronal process, often with side branches and more than one branching point, described in brains of patients with Parkinson's disease. Lewy neurites stain positively for ubiquitin in brainstem and forebrain regions affected in Parkinson's disease. |
| Lateral element | A proteinaceous core found between sister chromatids during meiotic prophase. |
| Integral component of membrane | The component of a membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Endosome | A membrane-bounded organelle to which materials ingested by endocytosis are delivered. |
| Cytoophidium | A subcellular filamentary structure where CTP synthase is compartmentalized in a range of organisms including bacteria, yeast, fruit fly, rat and human. |
| Synaptic ribbon | |
| Basement membrane | A thin layer of dense material found in various animal tissues interposed between the cells and the adjacent connective tissue. It consists of the basal lamina plus an associated layer of reticulin fibers. |
| Intracellular canaliculus | An apical plasma membrane part that forms a narrow enfolded luminal membrane channel, lined with numerous microvilli, that appears to extend into the cytoplasm of the cell. A specialized network of intracellular canaliculi is a characteristic feature of parietal cells of the gastric mucosa in vertebrates. |
| R2TP complex | A highly conserved protein complex comprised of two ATP-dependent DNA helicases (Rvb1p and Rvb2p in yeast, Pontin52 and Reptin52 in humans), Pih1p in yeast or PIH1D1 in humans, and Tah1 in yeast or RPAP3 in humans. The complex associates with Hsp90 and is thought to have a role in assembly of large protein or protein/nucleic acid complexes. In this role it is involved in multiple processes such as box C/D snoRNP biogenesis, phosphatidylinositol-3 kinase-related protein kinase (PIKK) signaling, RNA polymerase II assembly, and others. |
| Dynactin complex | A 20S multiprotein assembly of total mass about 1.2 MDa that activates dynein-based activity in vivo. A large structural component of the complex is an actin-like 40 nm filament composed of actin-related protein, to which other components attach. |
| Photosystem | A complex located in a photosynthetic membrane that consists of a photoreaction center associated with accessory pigments and electron carriers. Examples of this component are found in Arabidopsis thaliana and in photosynthetic bacterial and archaeal species. |
| Nuclear lumen | The volume enclosed by the nuclear inner membrane. |
| CCAAT-binding factor complex | A heteromeric transcription factor complex that binds to the CCAAT-box upstream of promoters; in Saccharomyces it activates the transcription of genes in response to growth in a nonfermentable carbon source; consists of four known subunits: HAP2, HAP3, HAP4 and HAP5. |
| Chaperonin ATPase complex | |
| Adherens junction | A cell junction at which anchoring proteins (cadherins or integrins) extend through the plasma membrane and are attached to actin filaments. |
| BMP receptor complex | A protein complex that acts as a receptor for bone morphogenetic proteins (BMPs); a homo- or heterodimer of type I and/or type II BMP receptor subunits. |
| Fc receptor complex | A protein complex composed of a subunit or subunits capable of binding the Fc portion of an immunoglobulin with additional signaling components. The complex functions as a receptor for immunoglobulin. |
| GroEL-GroES complex | |
| ESCRT III complex | An endosomal sorting complex required for transport. Consists of two soluble subcomplexes of highly charged coiled-coil proteins and is required for sorting and/or concentration of multivesicular body (MVB) cargoes. |
| Mitochondrial nucleoid | The region of a mitochondrion to which the DNA is confined. |
| Caspase complex | |
| Mitochondrial chromosome | A chromosome found in the mitochondrion of a eukaryotic cell. |
| ESCRT complex | An endosomal sorting complex required for transport. |
| Glutaminase complex | |
| Pellicle | The structure enclosing an apicomplexan parasite cell; consists of the cell membrane with its associated infrastructure of microtubules, microfilaments and other organelles. |
| 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase complex | A homodimeric, bifunctional enzyme complex which catalyzes the synthesis and degradation of fructose 2,6-bisphosphate, and is required for both glycolysis and gluconeogenesis. |
| Exodeoxyribonuclease V complex | |
| Phagophore | |
| Weibel-Palade body | A large, elongated, rod-shaped secretory granule characteristic of vascular endothelial cells that contain a number of structurally and functionally distinct proteins, of which the best characterized are von Willebrand factor (VWF) and P-selectin. Weibel-Palade bodies are formed from the trans-Golgi network in a process that depends on VWF, which is densely packed in a highly organized manner, and on coat proteins that remain associated with the granules. Upon cell stimulation, regulated exocytosis releases the contained proteins to the cell surface, where they act in the recruitment of platelets and leukocytes and in inflammatory and vasoactive responses. |
| 4-aminobutyrate transaminase complex | A homodimeric protein complex that possesses 4-aminobutyrate transaminase activity. |
| Nucleoid | The region of a virus, bacterial cell, mitochondrion or chloroplast to which the nucleic acid is confined. |
| Contractile actin filament bundle | |
| Stress fiber | A contractile actin filament bundle that consists of short actin filaments with alternating polarity, cross-linked by alpha-actinin and possibly other actin bundling proteins, and with myosin present in a periodic distribution along the fiber. |
| Inward rectifying potassium channel | |
| Desmosome | A cell-cell junction in which: on the cytoplasmic surface of each interacting plasma membrane is a dense plaque composed of a mixture of intracellular anchor proteins; a bundle of keratin intermediate filaments is attached to the surface of each plaque; transmembrane adhesion proteins of the cadherin family bind to the plaques and interact through their extracellular domains to hold the adjacent membranes together by a Ca2+-dependent mechanism. |
| Actin filament bundle | An assembly of actin filaments that are on the same axis but may be oriented with the same or opposite polarities and may be packed with different levels of tightness. |
| Proteasome activator complex | A multisubunit complex that activates the hydrolysis of small nonubiquitinated peptides by binding to the proteasome core complex. |
| Dbf4-dependent protein kinase complex | A heterodimeric protein complex required for the activation of DNA replication origins; comprises a catalytic subunit and a regulatory subunit (in Saccharomyces, Cdc7p and Dbf4p, respectively); complexes identified in other species generally contain proteins related to the Saccharomyces proteins. |
| Protein phosphatase type 2A complex | A protein complex that has protein serine/threonine phosphatase activity that is polycation-stimulated (PCS), being directly stimulated by protamine, polylysine, or histone H1; it constitutes a subclass of several enzymes activated by different histones and polylysine, and consists of catalytic, scaffolding, and regulatory subunits. The catalytic and scaffolding subunits form the core enzyme, and the holoenzyme also includes the regulatory subunit. |
| MPT synthase complex | |
| Upstream stimulatory factor complex | |
| Melanosome | A tissue-specific, membrane-bounded cytoplasmic organelle within which melanin pigments are synthesized and stored. Melanosomes are synthesized in melanocyte cells. |
| Serotonin receptor complex | |
| Lipid droplet | |
| NatA complex | A conserved complex that catalyzes the transfer of an acetyl group to an N-terminal Ser, Ala, Gly, or Thr residue of a protein acceptor molecule. In Saccharomyces the complex includes Nat1p and Ard1p, and may contain additional proteins. |
| DSIF complex | A heterodimeric protein complex formed of Spt4 and Spt5 proteins which is expressed in eukaryotes from yeast to man. DSIF is an inhibitory elongation factor that promotes RNA polymerase II transcriptional pausing, but can also stimulate transcriptional elongation under certain conditions, and may play a role in RNA processing via its physical association with mRNA capping enzymes. |
| Bacterial degradosome | |
| Myosin II complex | A myosin complex containing two class II myosin heavy chains, two myosin essential light chains and two myosin regulatory light chains. Also known as classical myosin or conventional myosin, the myosin II class includes the major muscle myosin of vertebrate and invertebrate muscle, and is characterized by alpha-helical coiled coil tails that self assemble to form a variety of filament structures. |
| Autolysosome | A type of secondary lysosome in which a primary lysosome has fused with the outer membrane of an autophagosome. It is involved in the second step of autophagy in which it degrades contents with acidic lysosomal hydrolases. |
| Condensed nuclear chromosome | A highly compacted molecule of DNA and associated proteins resulting in a cytologically distinct structure that remains in the nucleus. |
| SUMO-targeted ubiquitin ligase complex | A nuclear ubiquitin ligase complex that specifically targets SUMOylated proteins; the complex is formed of homodimers or heterodimers of RNF4 family ubiquitin ligases and is conserved in eukaryotes. |
| INO80-type complex | A chromatin remodeling protein complex initially purified from S. cerevisiae and containing more than 10 subunits, including the SWR1-related complexes. INO80 (inositol requiring 80)-type complexes have diverse functions, including promoting transcriptional activation and DNA repair. |
| Cytoplasmic exosome (RNase complex) | Complex of 3'-5' exoribonucleases found in the cytoplasm. |
| Spliceosomal complex | Any of a series of ribonucleoprotein complexes that contain RNA and small nuclear ribonucleoproteins (snRNPs), and are formed sequentially during the splicing of a messenger RNA primary transcript to excise an intron. |
| Calprotectin complex | |
| RZZ complex | |
| Meiotic cohesin complex | A cohesin complex that mediates sister chromatid cohesion during meiosis; has a subunit composition distinct from that of the mitotic cohesin complex. |
| Pigment granule | A small, subcellular membrane-bounded vesicle containing pigment and/or pigment precursor molecules. Pigment granule biogenesis is poorly understood, as pigment granules are derived from multiple sources including the endoplasmic reticulum, coated vesicles, lysosomes, and endosomes. |
| Thylakoid membrane | The pigmented membrane of any thylakoid. |
| NarGHI complex | |
| Connexin complex | |
| mRNA cleavage stimulating factor complex | A protein complex required for mRNA cleavage but not for poly(A) addition. |
| CatSper complex | A sperm-specific voltage-gated calcium channel that controls the intracellular calcium ion concentration and, thereby, the swimming behavior of sperm. Consists of a heteromeric tetramer surrounding a calcium ion- selective pore. May also contain additional auxiliary subunits. |
| Somatodendritic compartment | The region of a neuron that includes the cell body (cell soma) and the dendrite, but excludes the axon. |
| Exosome (RNase complex) | Complex of 3'-5' exoribonucleases. |
| Catalase complex | |
| Activin complex | A nonsteroidal regulator, composed of two covalently linked inhibin beta subunits, inhibin beta-A and inhibin beta-B (sometimes known as activin beta or activin/inhibin beta). There are three forms of activin complex, activin A, which is composed of 2 inhibin beta-A subunits, activin B, which is composed of 2 inhibin beta-B subunits, and activin AB, which is composed of an inhibin beta-A and an inhibin beta-B subunit. |
| GATOR1 complex | |
| Kinetochore | A multisubunit complex that is located at the centromeric region of DNA and provides an attachment point for the spindle microtubules. |
| Plasma membrane respirasome | |
| L-cysteine desulfurase complex | A protein complex capable of cysteine desulfurase activity decomposing L-cysteine to L-alanine and sulfur. It belongs to a ubiquitous family of pyridoxal 5-phosphate (PLP)-dependent enzymes. In E. coli it consists of a SufS dimer. |
| Condensed chromosome, centromeric region | The region of a condensed chromosome that includes the centromere and associated proteins, including the kinetochore. In monocentric chromosomes, this region corresponds to a single area of the chromosome, whereas in holocentric chromosomes, it is evenly distributed along the chromosome. |
| Chromosomal region | Any subdivision of a chromosome along its length. |
| Sarcoglycan complex | A protein complex formed of four sarcoglycans plus sarcospan; there are six known sarcoglycans: alpha-, beta-, gamma-, delta-, epsilon- and zeta-sarcoglycan; all are N-glycosylated single-pass transmembrane proteins. The sarcoglycan-sarcospan complex is a subcomplex of the dystrophin glycoprotein complex, and is fixed to the dystrophin axis by a lateral association with the dystroglycan complex. |
| Activin A complex | A nonsteroidal regulator, composed of two covalently linked inhibin beta-A subunits (sometimes known as activin beta-A or activin/inhibin beta-A). |
| Mitochondrial outer membrane | The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope. |
| ribonucleoside-diphosphate reductase complex | An enzyme complex composed of 2-4 or more subunits, which usually contains nonheme iron and requires ATP for catalysis. Catalyzes the formation of 2'-deoxyribonucleoside diphosphate from ribonucleoside diphosphate, using either thioredoxin disulfide or glutaredoxin disulfide as an acceptor. |
| Nitrate reductase complex | An enzyme complex that catalyzes the formation of nitrate from nitrite with the concomitant reduction of an acceptor. |
| Organelle outer membrane | The outer, i.e. cytoplasm-facing in a cellular organelle, lipid bilayer of an organelle envelope. |
| Dendritic tree | The entire complement of dendrites for a neuron, consisting of each primary dendrite and all its branches. |
| HCN channel complex | |
| Outer membrane | The external membrane of Gram-negative bacteria or certain organelles such as mitochondria and chloroplasts; freely permeable to most ions and metabolites. |
| Replication fork | The Y-shaped region of a replicating DNA molecule, resulting from the separation of the DNA strands and in which the synthesis of new strands takes place. Also includes associated protein complexes. |
| Calcitonin family receptor complex | |
| Dendrite | A neuron projection that has a short, tapering, often branched, morphology, receives and integrates signals from other neurons or from sensory stimuli, and conducts a nerve impulse towards the axon or the cell body. In most neurons, the impulse is conveyed from dendrites to axon via the cell body, but in some types of unipolar neuron, the impulse does not travel via the cell body. |
| NLRP1 inflammasome complex | A protein complex that consists of two components, NLRP1 (NALP1) and caspase-1 or caspase-5. The exact mechanisms of NLRP1 activation remain obscure, but potassium ion efflux appears to be essential. |
| Protein N-acetylglucosaminyltransferase complex | Heterotrimeric enzyme complex, which in humans is composed of two large subunits of the same size, and one smaller subunit. Functions in the addition of nucleotide-activated sugars onto the polypeptide. |
| Complement component C1q complex | |
| 5-lipoxygenase complex | |
| Eukaryotic translation initiation factor 2B complex | A multisubunit guanine nucleotide exchange factor which catalyzes the exchange of GDP bound to initiation factor eIF2 for GTP, generating active eIF2-GTP. In humans, it is composed of five subunits, alpha, beta, delta, gamma and epsilon. |
| thioredoxin-disulfide reductase complex | |
| Lamellar body | A membrane-bounded organelle, specialized for the storage and secretion of various substances (surfactant phospholipids, glycoproteins and acid phosphates) which are arranged in the form of tightly packed, concentric, membrane sheets or lamellae. Has some similar properties to, but is distinct from, a lysosome. |
| Cation channel complex | An ion channel complex through which cations pass. |
| pre-B cell receptor complex | An immunoglobulin-like complex that is present in at least the plasma membrane of pre-B cells, and that is composed of two identical immunoglobulin heavy chains and two surrogate light chains, each composed of the lambda-5 and VpreB proteins, and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| Nuclear lamina | The fibrous, electron-dense layer lying on the nucleoplasmic side of the inner membrane of a cell nucleus, composed of lamin filaments. The polypeptides of the lamina are thought to be concerned in the dissolution of the nuclear envelope and its re-formation during mitosis. The lamina is composed of lamin A and lamin C filaments cross-linked into an orthogonal lattice, which is attached via lamin B to the inner nuclear membrane through interactions with a lamin B receptor, an IFAP, in the membrane. |
| Ion channel complex | A protein complex that spans a membrane and forms a water-filled channel across the phospholipid bilayer allowing selective ion transport down its electrochemical gradient. |
| Mitochondrial matrix | The gel-like material, with considerable fine structure, that lies in the matrix space, or lumen, of a mitochondrion. It contains the enzymes of the tricarboxylic acid cycle and, in some organisms, the enzymes concerned with fatty acid oxidation. |
| Plastid | Any member of a family of organelles found in the cytoplasm of plants and some protists, which are membrane-bounded and contain DNA. Plant plastids develop from a common type, the proplastid. |
| Ribbon synapse | Type of synapse characterized by an electron-dense ribbon, lamella (bar) or spherical body in the presynaptic process cytoplasm. |
| NatB complex | A conserved complex that catalyzes the transfer of an acetyl group to the N-terminal residue of a protein acceptor molecule that has a Met-Glu, Met-Asp, Met-Asn, or Met-Met N-terminus. In Saccharomyces the complex includes Nat3p and Mdm20p. |
| Dendritic spine | Protrusion from a dendrite. Spines are specialised subcellular compartments involved in the synaptic transmission. They are linked to the dendritic shaft by a restriction. Because of their bulb shape, they function as a biochemical and an electrical compartment. Spine remodeling is though to be involved in synaptic plasticity. |
| Neuron spine | A small membranous protrusion, often ending in a bulbous head and attached to the neuron by a narrow stalk or neck. |
| N-terminal protein acetyltransferase complex | A complex that catalyzes the transfer of an acetyl group to the N-terminal residue of a protein acceptor molecule. |
| pre-T cell receptor complex | A receptor complex found on immature T cells consisting of a T cell receptor beta chain and the pre-TCR-alpha chain, along with additional signaling components including CD3 family members and additional signaling proteins. |
| iron-sulfur cluster assembly complex | |
| Respirasome | |
| Eukaryotic translation initiation factor 3 complex | A complex of several polypeptides that plays at least two important roles in protein synthesis: First, eIF3 binds to the 40S ribosome and facilitates loading of the Met-tRNA/eIF2.GTP ternary complex to form the 43S preinitiation complex. Subsequently, eIF3 apparently assists eIF4 in recruiting mRNAs to the 43S complex. The eIF3 complex contains five conserved core subunits, and may contain several additional proteins; the non-core subunits are thought to mediate association of the complex with specific sets of mRNAs. |
| Neuron projection terminus | The specialized, terminal region of a neuron projection such as an axon or a dendrite. |
| Discoidal high-density lipoprotein particle | A newly formed high-density lipoprotein particle; consists of a phospholipid bilayer surrounded by two or more APOA1 molecules. The discoidal HDL particle is formed when lipid-free or lipid-poor APOA1 acquires phospholipids and unesterified cholesterol from either cell membranes or triglyceride-rich lipoproteins (undergoing lipolysis by lipoprotein lipase). |
| SMAD protein complex | A protein complex that consists of SMAD proteins; may be homomeric or heteromeric. |
| Centrosome | A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle. |
| NPHP complex | |
| Stereocilium bundle | An actin-based, cross-linked cellular protrusion on the apical surface of auditory and vestibular hair cells. Stereocilium bundles act as mechanosensory organelles by responding to fluid motion or fluid pressure changes. |
| SNARE complex | A protein complex involved in membrane fusion; a stable ternary complex consisting of a four-helix bundle, usually formed from one R-SNARE and three Q-SNAREs with an ionic layer sandwiched between hydrophobic layers. One well-characterized example is the neuronal SNARE complex formed of synaptobrevin 2, syntaxin 1a, and SNAP-25. |
| Paranodal junction | A highly specialized cell-cell junction found in vertebrates, which forms between a neuron and a glial cell, and has structural similarity to Drosophila septate junctions. It flanks the node of Ranvier in myelinated nerve and electrically isolates the myelinated from unmyelinated nerve segments and physically separates the voltage-gated sodium channels at the node from the cluster of potassium channels underneath the myelin sheath. |
| Procentriole | |
| MutS complex | |
| Chromosome passenger complex | A eukaryotically conserved protein complex that localizes to kinetochores in early mitosis, the spindle mid-zone in anaphase B and to the telophase midbody. It has been proposed that the passenger complex coordinates various events based on its location to different structures during the course of mitosis. Complex members include the BIR-domain-containing protein Survivin, Aurora kinase, INCENP and Borealin. |
| Dihydrolipoyl dehydrogenase complex | A protein complex that possesses alpha-ketoglutarate dehydrogenase activity. |
| Seh1-associated complex | A protein complex that associates dynamically with the vacuolar membrane, and is proposed to have a role in membrane-associated trafficking or regulatory processes. In S. cerevisiae the complex contains Seh1p, Sec13p, Npr2p, Npr3p, Iml1p, Mtc5p, Rtc1p, and Sea4p. |
| interleukin-27 complex | A protein complex that is composed of an interleukin-27p28 subunit (product of the IL27 gene) and an EBI3 subunit and is secreted into the extracellular space. |
| Secondary lysosome | Vacuole formed by the fusion of a lysosome with an organelle (autosome) or with a primary phagosome. |
| Neutrophil extracellular trap | |
| Subcortical maternal complex | |
| Polycystin complex | A stable heterodimeric complex composed of polycystin-1 and polycystin-2. |
| CENP-A containing chromatin | |
| chromosome, centromeric core domain | The innermost portion of the centromeric region of a chromosome, encompassing the core region of a chromosome centromere and the proteins that bind to it. |
| Chloroplast | A chlorophyll-containing plastid with thylakoids organized into grana and frets, or stroma thylakoids, and embedded in a stroma. |
| Extracellular non-membrane-bounded organelle | Organized structure of distinctive morphology and function, not bounded by a lipid bilayer membrane and occurring outside the cell. |
| Proteasome core complex | A multisubunit barrel shaped endoprotease complex, which is the core of the proteasome complex. |
| Excitatory synapse | A synapse in which an action potential in the presynaptic cell increases the probability of an action potential occurring in the postsynaptic cell. |
| Integrin complex | A protein complex that is composed of one alpha subunit and one beta subunit, both of which are members of the integrin superfamily of cell adhesion receptors; the complex spans the plasma membrane and binds to extracellular matrix ligands, cell-surface ligands, and soluble ligands. |
| Microtubule organizing center | An intracellular structure that can catalyze gamma-tubulin-dependent microtubule nucleation and that can anchor microtubules by interacting with their minus ends, plus ends or sides. |
| U1 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U1. |
| Peroxisomal membrane | The lipid bilayer surrounding a peroxisome. |
| Endopeptidase complex | |
| PSII associated light-harvesting complex II | Protein-pigment complex associated with photosystem II. |
| Microbody membrane | The lipid bilayer surrounding a microbody. |
| Stereocilium | An actin-based protrusion from the apical surface of auditory and vestibular hair cells. Bundles of stereocilia act as mechanosensory organelles. |
| Sarcoplasmic reticulum membrane | The lipid bilayer surrounding the sarcoplasmic reticulum. |
| Mitochondrial permeability transition pore complex | A protein complex that connects the inner and outer membranes of animal mitochondria and acts as a pore that can open transiently to allow free diffusion of solutes between the mitochondrial matrix and the cytosol. The pore complex is formed of the voltage-dependent anion channel (VDAC), the adenine nucleotide translocase (ANT) and cyclophilin-D (CyP-D). |
| Slx1-Slx4 complex | A heterodimeric protein complex that possesses an endonuclease activity that specifically cleaves certain types of branched DNA structures; because such structures often form during the replication ribosomal DNA (rDNA) repeats, the complex plays a role in the maintenance of rDNA. The subunits are known as Slx1 and Slx 4 in budding and fission yeasts, and are conserved in eukaryotes. |
| Organelle lumen | The internal volume enclosed by the membranes of a particular organelle; includes the volume enclosed by a single organelle membrane, e.g. endoplasmic reticulum lumen, or the volume enclosed by the innermost of the two lipid bilayers of an organelle envelope, e.g. nuclear lumen. |
| Intracellular organelle lumen | An organelle lumen that is part of an intracellular organelle. |
| membrane-enclosed lumen | The enclosed volume within a sealed membrane or between two sealed membranes. Encompasses the volume enclosed by the membranes of a particular organelle, e.g. endoplasmic reticulum lumen, or the space between the two lipid bilayers of a double membrane surrounding an organelle, e.g. nuclear envelope lumen. |
| ESCRT I complex | An endosomal sorting complex required for transport. It consists of the class E vacuolar protein sorting (Vps) proteins and interacts with ubiquitinated cargoes. |
| Fatty acid synthase complex | A multienzyme complex that catalyses the synthesis of fatty acids from acetyl CoA. |
| mRNA cleavage and polyadenylation specificity factor complex | A multisubunit complex that binds to the canonical AAUAAA hexamer and to U-rich upstream sequence elements on the pre-mRNA, thereby stimulating the otherwise weakly active and nonspecific polymerase to elongate efficiently RNAs containing a poly(A) signal. |
| PRC1 complex | A multiprotein complex that mediates monoubiquitination of lysine residues of histone H2A (lysine-118 in Drosophila or lysine-119 in mammals). The complex is required for stable long-term maintenance of transcriptionally repressed states and is involved in chromatin remodeling. |
| Cornified envelope | A type of plasma membrane that has been modified through addition of distinct intracellular and extracellular components, including ceramide, found in cornifying epithelial cells (corneocytes). |
| MCM complex | A hexameric protein complex required for the initiation and regulation of DNA replication. |
| CENP-A containing nucleosome | A form of nucleosome located only at the centromere, in which the histone H3 is replaced by the variant form CENP-A (sometimes known as CenH3). |
| Thylakoid light-harvesting complex | A thylakoid membrane complex of chlorophylls a and b together with chlorophyll a-b binding proteins. In addition, LHCs contain a number of other proteins, the function of which is speculative, together with accessory pigments. The LHCs capture and transfer energy to photosystems I and II. An example of this is found in Arabidopsis thaliana. |
| Peptidase complex | |
| NuRD complex | An approximately 2 MDa multi-subunit complex that exhibits ATP-dependent chromatin remodeling activity in addition to histone deacetylase (HDAC) activity, and has been shown to establish transcriptional repression of a number of target genes in vertebrates, invertebrates and fungi. Amongst its subunits, the NuRD complex contains histone deacetylases, histone binding proteins and Mi-2-like proteins. |
| CHD-type complex | A SWI/SNF-type complex that contains a subunit from the CHD(Chromodomain helicase DNA-binding) family. The CHD family is characterized by two signature sequence motifs: tandem chromodomains located in the N-terminal region, and the SNF2-like ATPase domain located in the central region of the protein structure. |
| Cell envelope | An envelope that surrounds a bacterial cell and includes the cytoplasmic membrane and everything external, encompassing the periplasmic space, cell wall, and outer membrane if present. |
| S100A8 complex | |
| Phospholamban complex | |
| THO complex | The THO complex is a nuclear complex that is required for transcription elongation through genes containing tandemly repeated DNA sequences. The THO complex is also part of the TREX (TRanscription EXport) complex that is involved in coupling transcription to export of mRNAs to the cytoplasm. In S. cerevisiae, it is composed of four subunits: Hpr1p, Tho2p, Thp1p, and Mft1p, while the human complex is composed of 7 subunits. |
| Axon | The long process of a neuron that conducts nerve impulses, usually away from the cell body to the terminals and varicosities, which are sites of storage and release of neurotransmitter. |
| Nuclear cap binding complex | A conserved heterodimeric protein complex that binds to the 5' terminal cap structure m7G(5')ppp(5')N of nascent eukaryotic RNA polymerase II transcripts such as pre-mRNA and U snRNA. The consists of proteins known as CBP20 and CBP80, binds to cap structures in the nucleus, and is involved in pre-mRNA splicing, 3'-end formation, and RNA nuclear export. |
| Type IV secretion system complex | A complex of proteins related to those involved in bacterial DNA conjugative transfer, that permits the transfer of DNA or proteins into the extracellular milieu or directly into host cells. In general the type IV complex forms a multisubunit cell-envelope-spanning structure composed of a secretion channel and often a pilus or other surface filament or protein(s). |
| Glutamate synthase complex (NADPH) | |
| U2AF complex | |
| magnesium-dependent protein serine/threonine phosphatase complex | |
| Presynapse | |
| Spindle | The array of microtubules and associated molecules that forms between opposite poles of a eukaryotic cell during mitosis or meiosis and serves to move the duplicated chromosomes apart. |
| Nuclear exosome targeting complex | |
| Zeta DNA polymerase complex | A heterodimeric DNA polymerase complex that catalyzes error-prone DNA synthesis in contexts such as translesion synthesis and double-stranded break repair. First characterized in Saccharomyces, in which the subunits are Rev3p and Rev7p; a third protein, Rev1p, is often associated with the polymerase dimer. |
| Swr1 complex | A multisubunit protein complex that is involved in chromatin remodeling. It is required for the incorporation of the histone variant H2AZ into chromatin. In S. cerevisiae, the complex contains Swr1p, a Swi2/Snf2-related ATPase, and 12 additional subunits. |
| Heterochromatin | A compact and highly condensed form of chromatin. |
| CENP-A recruiting complex | |
| Paraflagellar rod | |
| CST complex | |
| Site of double-strand break | A region of a chromosome at which a DNA double-strand break has occurred. DNA damage signaling and repair proteins accumulate at the lesion to respond to the damage and repair the DNA to form a continuous DNA helix. |
| Glycoprotein Ib-IX-V complex | |
| Endoplasmic reticulum-plasma membrane contact site | |
| Mitotic checkpoint complex | A multiprotein complex that functions as a mitotic checkpoint inhibitor of the anaphase-promoting complex/cyclosome (APC/C). In budding yeast this complex consists of Mad2p, Mad3p, Bub3p and Cdc20p, and in mammalian cells it consists of MAD2, BUBR1, BUB3, and CDC20. |
| Acrosomal vesicle | A structure in the head of a spermatozoon that contains acid hydrolases, and is concerned with the breakdown of the outer membrane of the ovum during fertilization. It lies just beneath the plasma membrane and is derived from the lysosome. |
| Centralspindlin complex | A heterotetrameric protein complex playing a key role in the formation of the central spindle in mitosis. Made up of two molecules each of a mitotic kinesin (ZEN-4 in Caenorhabditis elegans or MKLP1 in mammals) and of two molecules each of a GTPase activating protein (GAP) factor (CYK-4 in Caenorhabditis elegans or MgcRacGAP in mammals). |
| Activin AB complex | A nonsteroidal regulator, composed of two covalently linked inhibin beta subunits (sometimes known as activin beta or activin/inhibin beta), inhibin beta-A and inhibin beta-B. |
| Glutamate synthase complex | |
| Protein serine/threonine phosphatase complex | A complex, normally consisting of a catalytic and a regulatory subunit, which catalyzes the removal of a phosphate group from a serine or threonine residue of a protein. |
| interleukin-35 complex | A protein complex that is composed of an interleukin-12 alpha subunit (p35, product of the IL12A gene) and an EBI3 subunit and is secreted into the extracellular space. |
| Site of DNA damage | |
| Potassium channel complex | An ion channel complex through which potassium ions pass. |
| Unconventional myosin complex | A portmanteau term for myosins other than myosin II. |
| Electron transfer flavoprotein complex | A protein complex containing flavin adenine dinucleotide (FAD) and acyl-CoA dehydrogenase, which form a system that oxidizes an acyl-CoA molecule and reduces ubiquinone and other acceptors in the mitochondrial electron transport system. |
| Glutamate decarboxylase complex | |
| Potassium ion-transporting ATPase complex | Protein complex that carries out the reaction: ATP + H2O + K+(out) = ADP + phosphate + K+(in). It is a high affinity potassium uptake system. The E. coli complex consists of 4 proteins: KdpA is the potassium ion translocase, KdpB is the ATPase, and KdpC and KdpF seem to be involved in assembly and stabilization of the complex. |
| MSL complex | A histone acetyltransferase complex that catalyzes the acetylation of a histone H4 lysine residue at position 16. In human, it contains the catalytic subunit MOF, and MSL1, MSL2 and MSL3. |
| Eukaryotic translation initiation factor 2 complex | Complex of three heterogeneous polypeptide chains, that form a ternary complex with initiator methionyl-tRNA and GTP. This ternary complex binds to free 40S subunit, which subsequently binds the 5' end of mRNA. |
| Tricarboxylic acid cycle enzyme complex | Any of the heteromeric enzymes that act in the TCA cycle. |
| Type III protein secretion system complex | A complex of approximately 20 proteins, most of which are located in the cytoplasmic membrane that carries out protein secretion in the bacterial type III secretion system; type III secretion also requires a cytoplasmic, probably membrane-associated ATPase. |
| U2 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U2. |
| MHC class I peptide loading complex | A large, multisubunit complex which consists of the MHC class I-beta 2 microglobulin dimer, the transporter associated with antigen presentation (TAP), tapasin (an MHC-encoded membrane protein), the chaperone calreticulin and the thiol oxidoreductase ERp57. Functions in the assembly of peptides with newly synthesized MHC class I molecules. |
| Centriole | A cellular organelle, found close to the nucleus in many eukaryotic cells, consisting of a small cylinder with microtubular walls, 300-500 nm long and 150-250 nm in diameter. It contains nine short, parallel, peripheral microtubular fibrils, each fibril consisting of one complete microtubule fused to two incomplete microtubules. Cells usually have two centrioles, lying at right angles to each other. At division, each pair of centrioles generates another pair and the twin pairs form the pole of the mitotic spindle. |
| Nuclear periphery | The portion of the nuclear lumen proximal to the inner nuclear membrane. |
| Signal recognition particle | A complex of protein and RNA which facilitates translocation of proteins across membranes. |
| Mitochondrial inner membrane | The inner, i.e. lumen-facing, lipid bilayer of the mitochondrial envelope. It is highly folded to form cristae. |
| Synaptic vesicle | A secretory organelle, some 50 nm in diameter, of presynaptic nerve terminals; accumulates in high concentrations of neurotransmitters and secretes these into the synaptic cleft by fusion with the 'active zone' of the presynaptic plasma membrane. |
| Phosphatidylinositol 3-kinase complex, class III | A phosphatidylinositol 3-kinase complex that contains a catalytic class III phosphoinositide 3-kinase (PI3K) subunit bound to a regulatory (adaptor) subunit. Additional adaptor proteins may be present. Class III PI3Ks have a substrate specificity restricted to phosphatidylinositol (PI). |
| Transverse filament | A structural unit of the synaptonemal complex that spans the regions between the lateral elements and connects them. |
| Clathrin complex | A protein complex that consists of three clathrin heavy chains and three clathrin light chains, organized into a symmetrical three-legged structure called a triskelion. In clathrin-coated vesicles clathrin is the main component of the coat and forms a polymeric mechanical scaffold on the vesicle surface. |
| interleukin-12 receptor complex | A protein complex that binds interleukin-12; comprises a beta1 and a beta2 subunit. |
| Microtubule | Any of the long, generally straight, hollow tubes of internal diameter 12-15 nm and external diameter 24 nm found in a wide variety of eukaryotic cells; each consists (usually) of 13 protofilaments of polymeric tubulin, staggered in such a manner that the tubulin monomers are arranged in a helical pattern on the microtubular surface, and with the alpha/beta axes of the tubulin subunits parallel to the long axis of the tubule; exist in equilibrium with pool of tubulin monomers and can be rapidly assembled or disassembled in response to physiological stimuli; concerned with force generation, e.g. in the spindle. |
| phenylalanine-tRNA ligase complex | |
| Succinate dehydrogenase complex (ubiquinone) | The enzyme that catalyzes the oxidation of succinate and ubiquinone to fumarate and ubiquinol; involved in aerobic respiration, repressed in anaerobic respiration. |
| Rhoptry neck | |
| MIS12/MIND type complex | A multiprotein kinetochore subcomplex that binds to centromeric chromatin and forms part of the inner kinetochore. It helps to recruit outer kinetochore subunits that will bind to microtubules. In humans, it consists of MIS12, DSN1, NSL1 and PMF1. |
| USH2 complex | |
| Secondary cell wall | A plant cell wall that is no longer able to expand and so does not permit growth. Secondary cell walls contain less pectin that primary cell walls. The secondary cell is mostly composed of cellulose and is strengthened with lignin. |
| Integrin alphaIIb-beta3 complex | An integrin complex that comprises one alphaIIb subunit and one beta3 subunit. |
| Integrin alpha5-beta1 complex | An integrin complex that comprises one alpha5 subunit and one beta1 subunit. |
| Late endosome | A prelysosomal endocytic organelle differentiated from early endosomes by lower lumenal pH and different protein composition. Late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center. |
| Cell leading edge | The area of a motile cell closest to the direction of movement. |
| Multivesicular body | A type of late endosome in which regions of the limiting endosomal membrane invaginate to form internal vesicles; membrane proteins that enter the internal vesicles are sequestered from the cytoplasm. |
| Ino80 complex | A multisubunit protein complex that contains the Ino80p ATPase; exhibits chromatin remodeling activity and 3' to 5' DNA helicase activity. |
| RSC-type complex | |
| Chloroplast thylakoid membrane protein complex | |
| Pore complex | Any small opening in a membrane that allows the passage of gases and/or liquids. |
| Proteasome accessory complex | A protein complex, that caps one or both ends of the proteasome core complex and regulates entry into, or exit from, the proteasome core complex. |
| Exocytic vesicle | A transport vesicle that mediates transport from an intracellular compartment to the plasma membrane, and fuses with the plasma membrane to release various cargo molecules, such as proteins or hormones, by exocytosis. |
| Tenascin complex | |
| COPII-coated ER to Golgi transport vesicle | |
| U7 snRNP | A ribonucleoprotein complex that contains the U7 snRNA and is required for the 3'-end processing of replication-dependent histone pre-mRNAs. |
| Organelle inner membrane | The inner, i.e. lumen-facing, lipid bilayer of an organelle envelope; usually highly selective to most ions and metabolites. |
| Nucleolus | A small, dense body one or more of which are present in the nucleus of eukaryotic cells. It is rich in RNA and protein, is not bounded by a limiting membrane, and is not seen during mitosis. Its prime function is the transcription of the nucleolar DNA into 45S ribosomal-precursor RNA, the processing of this RNA into 5.8S, 18S, and 28S components of ribosomal RNA, and the association of these components with 5S RNA and proteins synthesized outside the nucleolus. This association results in the formation of ribonucleoprotein precursors; these pass into the cytoplasm and mature into the 40S and 60S subunits of the ribosome. |
| HOPS complex | A multimeric protein complex that associates with the vacuolar membrane, late endosomal (multivesicular body) and lysosomal membranes. HOPS is a tethering complex involved in vesicle fusion. |
| Mitochondrial ribonuclease P complex | A ribonuclease P complex located in the mitochondrion of a eukaryotic cell, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. The subunit composition of mitochondrial ribonuclease P complexes varies between species, but the complex often contains a single RNA molecule and a single protein molecule. |
| gamma-tubulin complex | A multiprotein complex composed of gamma-tubulin and other non-tubulin proteins. Gamma-tubulin complexes are localized to microtubule organizing centers, and play an important role in the nucleation of microtubules. The number and complexity of non-tubulin proteins associated with these complexes varies between species. |
| Delta1 complex | A protein complex that consists of homodimer of the Notch ligand Delta1. |
| Sodium channel complex | An ion channel complex through which sodium ions pass. |
| Septin cytoskeleton | The part of the cytoskeleton (the internal framework of a cell) composed of septins and associated proteins. Includes septin cytoskeleton-associated complexes. |
| BBSome | A protein complex that associates with the primary cilium and is involved in cilium biogenesis; consists of seven conserved proteins: BBS1, BBS2, BBS4, BBS5, BBS7, BBS8 and BBS9. |
| Condensin complex | A multisubunit protein complex that plays a central role in chromosome condensation. |
| NMS complex | A supercomplex formed by the association of two subcomplexes (known as MIND and Ndc80 in Schizosaccharomyces) with additional proteins at the kinetochores of condensed nuclear chromosomes. |
| Clathrin coat | A membrane coat found on coated pits and some coated vesicles; consists of polymerized clathrin triskelions, each comprising three clathrin heavy chains and three clathrin light chains, linked to the membrane via one of the AP adaptor complexes. |
| CBM complex | A protein complex comprising Carma1, Bcl10 and MALT1; plays a role in signal transduction during NF-kappaB activation. |
| Peroxisomal importomer complex | |
| Podocyte foot | |
| RNA polymerase II, holoenzyme | |
| laminin-2 complex | A laminin complex composed of alpha2, beta1 and gamma1 polypeptide chains. |
| Checkpoint clamp complex | Conserved heterotrimeric complex of PCNA-like proteins that is loaded onto DNA at sites of DNA damage. |
| Condensed chromosome | A highly compacted molecule of DNA and associated proteins resulting in a cytologically distinct structure. |
| NURF complex | An ISWI complex that contains an ATPase subunit of the ISWI family (SNF2L in mammals), a NURF301 homolog (BPTF in humans), and additional subunits, though the composition of these additional subunits varies slightly with species. NURF is involved in regulation of transcription from TRNA polymerase II promoters. |
| Cellulosome | An extracellular multi-enzyme complex containing up to 11 different enzymes aligned on a non-catalytic scaffolding glycoprotein. Functions to hydrolyze cellulose. |
| Cdc73/Paf1 complex | A multiprotein complex that associates with RNA polymerase II and general RNA polymerase II transcription factor complexes and may be involved in both transcriptional initiation and elongation. In Saccharomyces the complex contains Paf1p, Cdc73p, Ctr9p, Rtf1p, and Leo1p. |
| Outer kinetochore | |
| Inner kinetochore | |
| Inhibin A complex | Heterodimeric hormone composed of an inhibin alpha subunit complexed with an inhibin beta-A subunit. |
| Integral component of endoplasmic reticulum membrane | The component of the endoplasmic reticulum membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| PML body | A class of nuclear body; they react against SP100 auto-antibodies (PML, promyelocytic leukemia); cells typically contain 10-30 PML bodies per nucleus; alterations in the localization of PML bodies occurs after viral infection. |
| Intrinsic component of endoplasmic reticulum membrane | The component of the endoplasmic reticulum membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor), which spans or is embedded in one or both leaflets of the membrane. |
| Lamellipodium | A thin sheetlike process extended by the leading edge of a crawling fibroblast; contains a dense meshwork of actin filaments. |
| gamma-tubulin small complex | A complex usually comprising two gamma-tubulin molecules and two conserved non-tubulin proteins. Some gamma-tubulin small complexes are thought to be the repeating unit making up the core of the gamma-tubulin ring complex. |
| S100A9 complex | |
| Membrane coat | Any of several different proteinaceous coats that can associate with membranes. Membrane coats include those formed by clathrin plus an adaptor complex, the COPI and COPII complexes, and possibly others. They are found associated with membranes on many vesicles as well as other membrane features such as pits and perhaps tubules. |
| 7SK snRNP | |
| Homomeric SMAD protein complex | |
| XRCC2-RAD51D complex | A heterodimeric DNA recombinase mediator complex that contains the Rad51 paralogs RAD51D and XRCC2, or orthologs thereof; conserved from fission yeast to human but absent from budding yeast. |
| Guanylate cyclase complex, soluble | Complex that possesses guanylate cyclase activity and is not bound to a membrane. |
| C zone | A region of the A band in which myosin-binding protein C is located and that can be seen by electron microscopy. This is a functional zone that also includes myosin. |
| Outer dynein arm | Outer arm structure present on the outer doublet microtubules of ciliary and flagellar axonemes. Outer dynein arms contain 2-3 heavy chains, two or more intermediate chains and a cluster of 4-8 light chains. Inner and outer dynein arms have different functions in the generation of microtubule-based motility. |
| HIR complex | A protein complex proposed to be involved in replication-independent nucleosome assembly, by promoting histone deposition onto DNA. For example, in Saccharomyces, the complex contains Hir1p, Hir2p, Hir3p, and Hpc2p. |
| MutSgamma complex | |
| Sarcolemma | The outer membrane of a muscle cell, consisting of the plasma membrane, a covering basement membrane (about 100 nm thick and sometimes common to more than one fiber), and the associated loose network of collagen fibers. |
| HDA1 complex | A tetrameric histone deacetylase complex that contains a Class II deacetylase catalytic subunit. In S. cerevisiae it is composed of two Hda1p subunits along with Hda2p and Hda3p. |
| Cilium | A specialized eukaryotic organelle that consists of a filiform extrusion of the cell surface and of some cytoplasmic parts. Each cilium is largely bounded by an extrusion of the cytoplasmic (plasma) membrane, and contains a regular longitudinal array of microtubules, anchored to a basal body. |
| Axonemal dynein complex | A dynein complex found in eukaryotic cilia and flagella; the motor domain heads interact with adjacent microtubules to generate a sliding force which is converted to a bending motion. May contain two or three dynein heavy chains as well as several light chains. |
| low-density lipoprotein receptor complex | |
| Set1C/COMPASS complex | A conserved protein complex that catalyzes methylation of histone H3. In Saccharomyces the complex contains Shg1p, Sdc1p, Swd1p, Swd2p, Swd3p, Spp1p, Bre2p, and the trithorax-related Set1p; in mammals it contains the catalytic subunit (SETD1A or SETD1B), WDR5, WDR82, RBBP5, ASH2L/ASH2, CXXC1/CFP1, HCFC1 and DPY30. |
| Swi5-Sfr1 complex | A conserved DNA recombinase mediator complex that contains two Swi5 monomers and one Sfr1 monomer in Schizosaccharomyces, or orthologs thereof (e.g. Sae3p and Mei5p in Saccharomyces). |
| Main axon | The main axonal trunk, as opposed to the collaterals. |
| Galectin complex | |
| G protein-coupled receptor complex | |
| Spanning component of plasma membrane | The component of the plasma membrane consisting of gene products and protein complexes that have some part that spans both leaflets of the membrane. |
| Fumarate reductase complex | A membrane-bound flavoenzyme complex consisting of four subunits, A, B, C, and D. A and B comprise the membrane-extrinsic catalytic domain and C (InterPro:IPR003510; InterPro:IPR004224) and D (InterPro:IPR003418) link the catalytic centers to the electron-transport chain. This family consists of the 13 kDa hydrophobic subunit D. This component may be required to anchor the catalytic components of the fumarate reductase complex to the cytoplasmic membrane. Fumarate reductase couples the reduction of fumarate to succinate to the oxidation of quinol to quinone, in a reaction opposite to that catalyzed by the related complex II of the respiratory chain (succinate dehydrogenase-(ubiquinone)). |
| Intercalated disc | A complex cell-cell junction at which myofibrils terminate in cardiomyocytes; mediates mechanical and electrochemical integration between individual cardiomyocytes. The intercalated disc contains regions of tight mechanical attachment (fasciae adherentes and desmosomes) and electrical coupling (gap junctions) between adjacent cells. |
| Chloroplast thylakoid membrane | The pigmented membrane of a chloroplast thylakoid. An example of this component is found in Arabidopsis thaliana. |
| Box C/D RNP complex | |
| Starch grain | Plant storage body for amylose and amylopectin, 1-100um in diameter. Also contains small amounts of enzymes, amino acids, lipids and nucleic acids. The shape of the grain varies widely amongst species, but is often spherical or disk-shaped. |
| Coated membrane | A single or double lipid bilayer with any of several different proteinaceous coats that can associate with membranes. Membrane coats include those formed by clathrin plus an adaptor complex, the COPI and COPII complexes. |
| Photosystem I | A photosystem that contains an iron-sulfur reaction center associated with accessory pigments and electron carriers. In cyanobacteria and chloroplasts, photosystem I functions as a light-dependent plastocyanin-ferredoxin oxidoreductase, transferring electrons from plastocyanin to ferredoxin; in photosynthetic bacteria that have only a single type I photosystem, such as the green sulfur bacteria, electrons can go either to ferredoxin (Fd) -> NAD+ or to menaquinone (MK) -> Cytb/FeS -> Cytc555 -> photosystem I (cyclic photophosphorylation). |
| Plastid thylakoid membrane | The lipid bilayer membrane of any thylakoid within a plastid. |
| BCOR complex | |
| TOM complex | |
| Spindle midzone | The area in the center of the spindle where the spindle microtubules from opposite poles overlap. |
| Super elongation complex | |
| ESCRT-0 complex | A protein complex required for the recycling of Golgi proteins, formation of lumenal membranes and sorting of ubiquitinated proteins into those membranes. This complex includes Vps1p and Hse1p in yeast and the Hrs and STAM proteins in mammals. |
| Ctf18 RFC-like complex | A heptameric complex related to replication factor C, which loads the DNA polymerase processivity factor proliferating cell nuclear antigen (PCNA) onto DNA and plays a vital role in chromosome cohesion. In Saccharomyces the subunits are known as Ctf18p, Rfc2p, Rfc3p, Rfc4p, Rfc5p, Dcc1p, and Ctf8p. |
| Transport vesicle | Any of the vesicles of the constitutive secretory pathway, which carry cargo from the endoplasmic reticulum to the Golgi, between Golgi cisternae, or to destinations within or outside the cell. |
| Cell wall | The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, most prokaryotic cells and some protozoan parasites, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan; in protozoan parasites such as Giardia species, it's made of carbohydrates and proteins. |
| ATR-ATRIP complex | A protein complex that contains the protein kinase ATR and ATR-interacting protein (ATRIP) and binds single-stranded DNA; ssDNA binding affinity is increased in the presence of replication protein A. |
| Microvesicle | |
| Inner mitochondrial membrane protein complex | |
| CORVET complex | A multimeric protein complex that acts as an endosomal tethering complex (CORVET = class C core vacuole/endosome tethering) by cooperating with Rab GTPases to capture endosomal vesicles and trap them prior to the action of SNAREs; the complex is involved in endo-lysosomal biogenesis and required for transport between endosome and vacuole. The Saccharomyces cerevisiae complex contains Vps8p, Vps3p, Pep5p, Vps16p, Pep3p, and Vps33p. |
| Fibrinogen complex | A highly soluble, elongated protein complex found in blood plasma and involved in clot formation. It is converted into fibrin monomer by the action of thrombin. In the mouse, fibrinogen is a hexamer, 46 nm long and 9 nm maximal diameter, containing two sets of nonidentical chains (alpha, beta, and gamma) linked together by disulfide bonds. |
| Node of Ranvier | An axon part that is a gap in the myelin where voltage-gated sodium channels cluster and saltatory conduction is executed. |
| SMC loading complex | A protein complex required for the loading of a structural maintenance of chromosome (SMC) complex, such as cohesin, condensin or SMC5/SMC6, onto DNA. Appears to be eukaryotically conserved. |
| dolichol-phosphate-mannose synthase complex | A protein complex that possesses dolichyl-phosphate beta-D-mannosyltransferase activity; contains a catalytic subunit, a regulatory subunit, and a third subunit that stabilizes the complex. In human and several other metazoa, the subunits are named DPM1, DPM2 and DPM3, respectively. |
| Neurofibrillary tangle | Intracellular knot or clump of neurofibrils seen in the cerebral cortex in Alzheimer's disease. |
| Kinesin complex | Any complex that includes a dimer of molecules from the kinesin superfamily, a group of related proteins that contain an extended region of predicted alpha-helical coiled coil in the main chain that likely produces dimerization. The native complexes of several kinesin family members have also been shown to contain additional peptides, often designated light chains as all of the noncatalytic subunits that are currently known are smaller than the chain that contains the motor unit. Kinesin complexes generally possess a force-generating enzymatic activity, or motor, which converts the free energy of the gamma phosphate bond of ATP into mechanical work. |
| BRCA1-A complex | A protein complex that contains the BRCA1-BARD1 heterodimer, RAP80/UIMC1, BRCC3/BRCC36, BRE/BRCC45, FAM175A/CCDC98/Abraxas and MERIT40/NBA1, and specifically recognizes and binds K63-linked polyubiquitin chains present on histone H2A and H2AX at DNA damage sites. |
| BLOC-3 complex | A protein complex required for the biogenesis of specialized organelles of the endosomal-lysosomal system, such as melanosomes and platelet dense granules. The human complex contains the Hps1 and Hps4 proteins. |
| Nuclear DNA-directed RNA polymerase complex | A protein complex, located in the nucleus, that possesses DNA-directed RNA polymerase activity. |
| Actomyosin contractile ring | A cytoskeletal structure composed of actin filaments and myosin that forms beneath the plasma membrane of many cells, including animal cells and yeast cells, in a plane perpendicular to the axis of the spindle, i.e. the cell division plane. Ring contraction is associated with centripetal growth of the membrane that divides the cytoplasm of the two daughter cells. In animal cells, the contractile ring is located inside the plasma membrane at the location of the cleavage furrow. In budding fungal cells, e.g. mitotic S. cerevisiae cells, the contractile ring forms beneath the plasma membrane at the mother-bud neck before mitosis. |
| Bounding membrane of organelle | The lipid bilayer that forms the outer-most layer of an organelle. |
| Mitochondrial prohibitin complex | A complex composed of two proteins, prohibitin 1 and prohibitin 2 (PHB1/PHB-1 and PHB2/PHB-2) that is highly conserved amongst eukaryotes and associated with the inner mitochondrial membrane. The mitochondrial prohibitin complex is a macromolecular supercomplex composed of repeating heterodimeric subunits of PHB1 and PHB2. The mitochondrial prohibitin complex plays a role in a number of biological processes, including mitochondrial biogenesis and function, development, replicative senescence, and cell death. |
| Proteasome complex | A large multisubunit complex which catalyzes protein degradation, found in eukaryotes, archaea and some bacteria. In eukaryotes, this complex consists of the barrel shaped proteasome core complex and one or two associated proteins or complexes that act in regulating entry into or exit from the core. |
| Chloroplast thylakoid | Sac-like membranous structures (cisternae) in a chloroplast combined into stacks (grana) and present singly in the stroma (stroma thylakoids or frets) as interconnections between grana. An example of this component is found in Arabidopsis thaliana. |
| COP9 signalosome | A protein complex that catalyzes the deneddylation of proteins, including the cullin component of SCF ubiquitin E3 ligase; deneddylation increases the activity of cullin family ubiquitin ligases. The signalosome is involved in many regulatory process, including some which control development, in many species; also regulates photomorphogenesis in plants; in many species its subunits are highly similar to those of the proteasome. |
| Ciliary rootlet | A cytoskeleton-like structure, originating from the basal body at the proximal end of a cilium, and extending proximally toward the cell nucleus. Rootlets are typically 80-100 nm in diameter and contain cross striae distributed at regular intervals of approximately 55-70 nm. |
| interleukin-4 receptor complex | A protein complex that binds interleukin-4 (IL-4) and consists of an alpha chain that binds IL-4 with high affinity and a gamma common chain that also forms part of the interleukin-2 receptor. |
| Axon terminus | Terminal inflated portion of the axon, containing the specialized apparatus necessary to release neurotransmitters. The axon terminus is considered to be the whole region of thickening and the terminal button is a specialized region of it. |
| interleukin-5 receptor complex | A protein complex that binds interleukin-3; comprises an alpha and a beta subunit. The alpha chain is specific to the interleukin-5 receptor, whereas the beta chain is shared with the receptors for granulocyte-macrophage colony-stimulating factor and interleukin-3. |
| Spherical high-density lipoprotein particle | A mature high-density lipoprotein (HDL) particle, converted from discoidal HDL particles following the esterification of cholesterol in the particle by phosphatidylcholine-sterol O-acyltransferase (lecithin cholesterol acyltransferase; LCAT). |
| Endoplasmic reticulum lumen | The volume enclosed by the membranes of the endoplasmic reticulum. |
| Vascular endothelial glycocalyx | |
| Plastid thylakoid | Any thylakoid within a plastid. |
| RecFOR complex | A heterotrimeric complex composed of the subunits RecF, RecO and RecR. Mediates the loading of RecA protein specifically onto SSB-coated gapped DNA during DNA repair. |
| Cell body | The portion of a cell bearing surface projections such as axons, dendrites, cilia, or flagella that includes the nucleus, but excludes all cell projections. |
| Radial spoke | Protein complex that links the outer microtubule doublet of the ciliary or flagellum axoneme with the sheath that surrounds the central pair of microtubules. Composed of a stalk that attaches to each doublet microtubule and a globular structure (spoke head) that projects toward the central pair of microtubules. |
| Nuclear inner membrane | The inner, i.e. lumen-facing, lipid bilayer of the nuclear envelope. |
| Intraciliary transport particle B | The larger subcomplex of the intraciliary transport particle; characterized complexes have molecular weights around 550 kDa. |
| Catenin complex | Complex of peripheral cytoplasmic proteins (alpha-, beta- and gamma-catenin) that interact with the cytoplasmic region of uvomorulin/E-cadherin to connect it to the actin cytoskeleton. |
| DNA-directed RNA polymerase complex | A protein complex that possesses DNA-directed RNA polymerase activity. |
| Pericentriolar material | A network of small fibers that surrounds the centrioles in cells; contains the microtubule nucleating activity of the centrosome. |
| Ski complex | A protein complex that regulates RNA degradation by the exosome complex. In Saccharomyces the complex has a heterotetrameric stoichiometry consisting of one copy each of Ski2p and Ski3 and two copies of Ski8p. |
| gamma-tubulin large complex | A complex of gamma tubulin and associated proteins thought to be formed by multimerization of gamma-tubulin small complexes. An example of this structure is found in Schizosaccharomyces pombe. |
| Organelle membrane contact site | A zone of apposition between the membranes of two organelles, structured by bridging complexes. Membrane contact sites (MCSs) are specialized for communication, including the efficient traffic of small molecules such as Ca2+ ions and lipids, as well as enzyme-substrate interactions. |
| Intraciliary transport particle | A nonmembrane-bound oligomeric protein complex that participates in bidirectional transport of molecules (cargo) along axonemal microtubules. |
| Tricellular tight junction | |
| RNA cap binding complex | Any protein complex that binds to a specialized RNA cap structure at any time in the lifetime of the RNA. |
| 90S preribosome | A large ribonucleoprotein complex considered to be the earliest preribosomal complex. In S. cerevisiae, it has a size of 90S and consists of the 35S pre-rRNA, early-associating ribosomal proteins most of which are part of the small ribosomal subunit, the U3 snoRNA and associated proteins. |
| NLRP6 inflammasome complex | |
| Pyruvate dehydrogenase complex | Complex that carries out the oxidative decarboxylation of pyruvate to form acetyl-CoA; comprises subunits possessing three catalytic activities: pyruvate dehydrogenase (E1), dihydrolipoamide S-acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). |
| PeBoW complex | A protein complex that is involved in coordinating ribosome biogenesis with cell cycle progression. In human, it is composed of Pes1, Bop1, and WDR12; in Saccharomyces the proteins are known as Nop7p, Erb1 and Ytm1 respectively. |
| Nuclear chromosome | A chromosome found in the nucleus of a eukaryotic cell. |
| Apical plasma membrane | The region of the plasma membrane located at the apical end of the cell. |
| Dosage compensation complex | A protein or protein-RNA complex that localizes to one or more of the sex chromosome(s), where it acts to normalize transcription between different sexes. |
| laminin-5 complex | A laminin complex composed of alpha3, beta3 and gamma2 polypeptide chains. |
| UDP-N-acetylglucosamine-lysosomal-enzyme N-acetylglucosaminephosphotransferase complex | A protein complex that possesses UDP-N-acetylglucosamine-lysosomal-enzyme N-acetylglucosaminephosphotransferase activity; the bovine complex contains disulfide-linked homodimers of 166- and 51-kDa subunits and two identical, noncovalently associated 56-kDa subunits. |
| chaperonin-containing T-complex | A multisubunit ring-shaped complex that mediates protein folding in the cytosol without a cofactor. |
| Apical complex | A group of cytoskeletal structures and associated membrane-bounded organelles found at the anterior end of adult obligate intracellular protozoan parasites in the phylum Apicomplexa. The apical complex is involved in attachment to and penetration of the host cell, and in parasite proliferation. |
| Intraciliary transport particle A | The smaller subcomplex of the intraciliary transport particle; characterized complexes have molecular weights of 710-760 kDa. |
| Type IV pilus | A short filamentous structure on the surface of a bacterial cell distinguished from other pili by post-translational N-methylation of the pilin monomers. |
| Apical part of cell | The region of a polarized cell that forms a tip or is distal to a base. For example, in a polarized epithelial cell, the apical region has an exposed surface and lies opposite to the basal lamina that separates the epithelium from other tissue. |
| BRCA1-BARD1 complex | A heterodimeric complex comprising BRCA1 and BARD1, which possesses ubiquitin ligase activity and is involved in genome maintenance, possibly by functioning in surveillance for DNA damage. |
| BRISC complex | A protein complex that contains the FAM175B/ABRO1, BRCC3/BRCC36, BRE/BRCC45 and MERIT40/NBA1 proteins, and specifically cleaves K63-linked polyubiquitin chains. |
| TRAPP complex | A large complex that acts as a tethering factor involved in transporting vesicles from the ER through the Golgi to the plasma membrane. A TRAPP (transport protein particle) complex has a core set of proteins which are joined by specific subunits depending on the cellular component where a given TRAPP complex is active. |
| ESCRT II complex | An endosomal sorting complex required for transport and functions downstream of ESCRT I complex. It consists of the class E vacuolar protein sorting (Vps) proteins and is required for the membrane recruitment of ESCRT III complex and binds to ubiquitinated cargoes. |
| plant-type vacuole membrane | The lipid bilayer surrounding a vacuole that retains the same shape regardless of cell cycle phase. The membrane separates its contents from the cytoplasm of the cell. An example of this component is found in Arabidopsis thaliana. |
| exon-exon junction complex | A multi-subunit complex deposited by the spliceosome upstream of messenger RNA exon-exon junctions. The exon-exon junction complex provides a binding platform for factors involved in mRNA export and nonsense-mediated mRNA decay. |
| NELF complex | A complex of five proteins, designated NELF-A, -B, -C, -D, and -E in human, that can physically associate with RNP polymerase II to induce transcriptional pausing. |
| Oligosaccharyltransferase complex | A protein complex that is found in the endoplasmic reticulum membrane of eukaryotes and transfers lipid-linked oligosaccharide precursor to asparagine residues on nascent proteins. In yeast, the complex includes at least nine different subunits, whereas in mammalian cells at least three different forms of the complex have been detected. |
| Nuclear pore | Any of the numerous similar discrete openings in the nuclear envelope of a eukaryotic cell, where the inner and outer nuclear membranes are joined. |
| Microtubule cytoskeleton | The part of the cytoskeleton (the internal framework of a cell) composed of microtubules and associated proteins. |
| MutLgamma complex | |
| Respiratory chain complex III | A protein complex that transfers electrons from ubiquinol to cytochrome c and translocates two protons across a membrane. The complex contains a core structure of three catalytic subunits: cytochrome b, the Rieske iron sulfur protein (ISP), and cytochrome c1, which are arranged in an integral membrane-bound dimeric complex; additional subunits are present, and vary among different species. |
| TTT complex | |
| iron-sulfur cluster transfer complex | |
| mRNA cap binding complex | Any protein complex that binds to an mRNA cap at any time in the lifetime of the mRNA. |
| Small ribosomal subunit | The smaller of the two subunits of a ribosome. |
| cell-cell contact zone | Extended zone of intimate apposition between two cells containing one or more types of intercellular junctions, e.g., the intercalated disk of muscle. |
| GARP complex | A quatrefoil tethering complex required for retrograde traffic from the early endosome back to the late Golgi and biogenesis of cytoplasmic vesicles. |
| Juxtaparanode region of axon | A region of an axon near a node of Ranvier that is between the paranode and internode regions. |
| Mitochondrial respiratory chain complex II, succinate dehydrogenase complex (ubiquinone) | |
| Photoreceptor outer segment | The outer segment of a vertebrate photoreceptor that contains discs of photoreceptive membranes. |
| interleukin-1 receptor complex | A protein complex that binds interleukin-1; comprises an alpha and a beta subunit. |
| BLOC-2 complex | A protein complex required for the biogenesis of specialized organelles of the endosomal-lysosomal system, such as melanosomes and platelet dense granules. The human complex contains the Hps3, Hps5, and Hps6 proteins; the mouse complex contains ru2 and ru. |
| Radial spoke head | |
| Myosin VI complex | A myosin complex containing one or more class VI myosin heavy chains and associated light chains. Myosin VI has a single IQ motif in the neck and a tail region with a coiled coil domain followed by a unique globular domain; a unique insertion that enables myosin VI to move towards the pointed or minus end of actin filaments. |
| Omegasome | Omega-shaped (as in the Greek capital letter) intracellular membrane-bounded organelle enriched in phosphatidylinositol 3-phosphate and dynamically connected to the endoplasmic reticulum. Omegasomes are the first step of the formation of autophagic vacuoles via the pre-autophagosomal structures. |
| P-body | |
| Mitochondrial degradosome | A mitochondrial protein complex with 3' to 5' exoribonuclease activity that participates in intron-independent turnover and processing of mitochondrial transcripts. In humans, the mitochondrial degradosome is a pentameric complex, and in yeast it exists as a heterodimer. |
| Spindle microtubule | Any microtubule that is part of a mitotic or meiotic spindle; anchored at one spindle pole. |
| Glucosidase II complex | A heterodimeric complex that catalyzes the trimming of glucose residues from N-linked core glycans on newly synthesized glycoproteins. |
| plant-type cell wall | A more or less rigid stucture lying outside the cell membrane of a cell and composed of cellulose and pectin and other organic and inorganic substances. |
| Delta DNA polymerase complex | A multimeric DNA polymerase enzyme complex which differs in composition amongst species; in humans it is a heterotetramer of four subunits of approximately 125, 50, 68 and 12kDa, while in S. cerevisiae, it has three different subunits which form a heterotrimer, and the active enzyme is a dimer of this heterotrimer. Functions in DNA replication, mismatch repair and excision repair. |
| Rpd3S/Clr6-CII complex | |
| Exoribonuclease complex | |
| Tripartite attachment complex | |
| Transmembrane transporter complex | A transmembrane protein complex which enables the transfer of a substance from one side of a membrane to the other. |
| GPI-anchor transamidase complex | An enzyme complex which in humans and yeast consists of at least five proteins; for example, the complex contains GAA1, GPI8, PIG-S, PIG-U, and PIG-T in human, and Gaa1p, Gab1p, Gpi8p, Gpi16p, and Gpi17p in yeast. Catalyzes the posttranslational attachment of the carboxyl-terminus of a precursor protein to a GPI-anchor. |
| Lysosomal membrane | The lipid bilayer surrounding the lysosome and separating its contents from the cell cytoplasm. |
| Lytic vacuole membrane | |
| Nuclear pore outer ring | A subcomplex of the nuclear pore complex (NPC) that forms the outer rings of the core scaffold, a lattice-like structure that gives the NPC its shape and strength. In S. cerevisiae, the two outer rings each contain multiple copies of the following proteins: Nup133p, Nup120p, Nup145Cp, Nup85p, Nup84p, Seh1p, and Sec13p. In vertebrates, the two outer rings each contain multiple copies of the following proteins: Nup133, Nup160, Nup96, Nup75, Nup107, Seh1, Sec13, Nup43, Nup37, and ALADIN. Components are arranged in 8-fold symmetrical 'spokes' around the central transport channel. A single 'spoke', can be isolated and is sometimes referred to as the Nup84 complex (S. cerevisiae) or the Nup107-160 complex (vertebrates). |
| snRNA-activating protein complex | A protein complex that recognizes the proximal sequence element of RNA polymerase II and III snRNA promoters. |
| follicle-stimulating hormone complex | A gonadotrophic glycoprotein hormone secreted, in mammals, by the anterior pituitary gland; consists of alpha and beta subunits, the latter of which confers hormonal specificity. |
| Noc4p-Nop14p complex | A heterodimer associated with precursors of the eukaryotic small ribosomal subunit, including the 90S preribosome; involved in small subunit biogenesis. |
| Curli | |
| Specific granule | Granule with a membranous, tubular internal structure, found primarily in mature neutrophil cells. Most are released into the extracellular fluid. Specific granules contain lactoferrin, lysozyme, vitamin B12 binding protein and elastase. |
| Nuclear speck | A discrete extra-nucleolar subnuclear domain, 20-50 in number, in which splicing factors are seen to be localized by immunofluorescence microscopy. |
| Ribosome | An intracellular organelle, about 200 A in diameter, consisting of RNA and protein. It is the site of protein biosynthesis resulting from translation of messenger RNA (mRNA). It consists of two subunits, one large and one small, each containing only protein and RNA. Both the ribosome and its subunits are characterized by their sedimentation coefficients, expressed in Svedberg units (symbol: S). Hence, the prokaryotic ribosome (70S) comprises a large (50S) subunit and a small (30S) subunit, while the eukaryotic ribosome (80S) comprises a large (60S) subunit and a small (40S) subunit. Two sites on the ribosomal large subunit are involved in translation, namely the aminoacyl site (A site) and peptidyl site (P site). Ribosomes from prokaryotes, eukaryotes, mitochondria, and chloroplasts have characteristically distinct ribosomal proteins. |
| KICSTOR complex | |
| DNA polymerase III, clamp loader complex | |
| Endoplasmic reticulum exit site | An endoplasmic reticulum part at which COPII-coated vesicles are produced. |
| NatC complex | A conserved complex that catalyzes the transfer of an acetyl group to the N-terminal residue of a protein acceptor molecule that has a Met-Ile, Met-Leu, Met-Trp, or Met-Phe N-terminus. In Saccharomyces the complex includes Mak3p, Mak10p, and Mak31p. |
| Bacterial biofilm matrix | |
| Synaptic cleft | The narrow gap that separates the presynaptic and postsynaptic membranes, into which neurotransmitter is released. |
| preribosome, small subunit precursor | A preribosomal complex consisting of 20S pre-rRNA, ribosomal proteins including late-associating small subunit proteins, and associated proteins; a precursor of the eukaryotic cytoplasmic small ribosomal subunit. |
| Sweet taste receptor complex | |
| EKC/KEOPS complex | A protein complex proposed to be involved in transcription as well as promoting telomere uncapping and telomere elongation. For example, in Saccharomyces cerevisiae the complex contains Bud32p, Kae1p, Gon7p, Cgi121p, and Pcc1p. |
| glutamate-cysteine ligase complex | An enzyme complex that catalyzes the ligation of glutamate to cysteine, forming glutamylcysteine. |
| Cytochrome b6f complex | Complex that transfers electrons from reduced plastoquinone to oxidized plastocyanin and translocates protons from the stroma to the lumen. The complex contains a core structure of three catalytic subunits: cytochrome b, the Rieske iron sulfur protein (ISP), and cytochrome f, which are arranged in an integral membrane-bound dimeric complex; additional subunits are present, and vary among different species. |
| Adrenomedullin receptor complex | |
| glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT) complex | An enzyme complex that catalyzes the transfer of GlcNAc from UDP-GlcNAc to an acceptor phosphatidylinositol, the first step in the production of GPI anchors for cell surface proteins. The complex contains PIG-A, PIG-C, PIG-H, PIG-Q, PIG-P, and DPM2 in human, and Eri1p, Gpi1p, Gpi2p, Gpi15p, Gpi19p, and Spt14p in budding yeast. |
| Ost-alpha/Ost-beta complex | A heterodimeric protein complex composed of Ost-alpha/SLC51A and Ost-beta/SLC51B subunits and involved in bile acid transport activity. |
| U5 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U5. |
| BLOC-1 complex | A protein complex required for the biogenesis of specialized organelles of the endosomal-lysosomal system, such as melanosomes and platelet dense granules. Many of the protein subunits are conserved between mouse and human; the mouse complex contains the Pallidin, Muted, Cappuccino, Dysbindin, Snapin, BLOS1, BLOS2, AND BLOS3 proteins. |
| Photosystem II oxygen evolving complex | A complex, composed of a cluster of manganese, calcium and chloride ions bound to extrinsic proteins, that catalyzes the splitting of water to O2 and 4 H+. In cyanobacteria there are five extrinsic proteins in OEC (PsbO, PsbP-like, PsbQ-like, PsbU and PsbV), while in plants there are only three (PsbO, PsbP and PsbQ). |
| T-tubule | Invagination of the plasma membrane of a muscle cell that extends inward from the cell surface around each myofibril. The ends of T-tubules make contact with the sarcoplasmic reticulum membrane. |
| GMP reductase complex | A protein complex which is capable of GMP reductase activity. It catalysis of the irreversible reaction: IMP + NADP(+) + NH(4)(+) <= GMP + 2 H(+) + NADPH. |
| Elg1 RFC-like complex | A pentameric complex related to replication factor C, which loads the DNA polymerase processivity factor proliferating cell nuclear antigen (PCNA) onto DNA and has roles in telomere length regulation and other aspects of genome stability. In Saccharomyces the subunits are known as Elg1p, Rfc2p, Rfc3p, Rfc4p, and Rfc5p. |
| Katanin complex | A complex possessing an activity that couples ATP hydrolysis to the severing of microtubules; usually a heterodimer comprising a catalytic subunit (often 60kDa) and a regulatory subunit (often 80 kDa). |
| voltage-gated sodium channel complex | A sodium channel in a cell membrane whose opening is governed by the membrane potential. |
| Deuterosome | A spherical, electron dense, cytoplasmic structure that is involved in de novo assembly of centrioles. |
| GABA-ergic synapse | |
| horsetail-astral microtubule array | An array of astral microtubules that emanates from the spindle pole body during meiosis and facilitates horsetail nuclear movement. |
| Endosome membrane | The lipid bilayer surrounding an endosome. |
| SAGA complex | A SAGA-type histone acetyltransferase complex that contains Spt8 (in budding yeast) or a homolog thereof; additional polypeptides include Spt group, consisting of Spt7, Spt3, and Spt20/Ada5, which interact with the TATA-binding protein (TBP); the Ada group, consisting of Ada1, Ada2, Ada3, Ada4/Gcn5, and Ada5/Spt20, which is functionally linked to the nucleosomal HAT activity; Tra1, an ATM/PI-3 kinase-related protein that targets DNA-bound activators for recruitment to promoters; the TBP-associated factor (TAF) proteins, consisting of Taf5, Taf6, Taf9, Taf10, and Taf12, which mediate nucleosomal HAT activity and are thought to help recruit the basal transcription machinery. |
| Oxoglutarate dehydrogenase complex | A complex of multiple copies of three enzymatic components: oxoglutarate dehydrogenase (lipoamide) ; EC:1.2.4.2 (E1), dihydrolipoamide S-succinyltransferase ; EC:2.3.1.61 (E2) and dihydrolipoamide dehydrogenase ; EC:1.8.1.4 (E3); catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and carbon dioxide (CO2). |
| Dense fibrillar component | A structure found in the nucleolus, which contains newly synthesized preribosomal RNA (pre-rRNA) and a collection of proteins. |
| Kinetochore microtubule | Any of the spindle microtubules that attach to the kinetochores of chromosomes by their plus ends, and maneuver the chromosomes during mitotic or meiotic chromosome segregation. |
| plant-type vacuole | A closed structure that is completely surrounded by a unit membrane, contains liquid, and retains the same shape regardless of cell cycle phase. An example of this structure is found in Arabidopsis thaliana. |
| Brush border | Dense covering of microvilli on the apical surface of epithelial cells in tissues such as the intestine, kidney, and choroid plexus; the microvilli aid absorption by increasing the surface area of the cell. |
| CAF-1 complex | A conserved heterotrimeric protein complex that promotes histone H3 and H4 deposition onto newly synthesized DNA during replication or DNA repair; specifically facilitates replication-dependent nucleosome assembly with the major histone H3 (H3.1). In many species the CAF-1 subunits are designated p150, p60, and p48. |
| TIM23 mitochondrial import inner membrane translocase complex | |
| Translation initiation complex | A ribonucleoprotein complex that contains a ribosome, mRNA, and initiator tRNA; the functional ribosome is at the AUG, with the methionyl/formyl-methionyl-tRNA positioned at the P site. |
| ASAP complex | A protein complex involved in regulation of mRNA processing and apoptosis. It binds to RNA in a sequence-independent manner and is recruited to the EJC prior to or during the splicing process. In humans the core proteins are RNPS1, SAP18 and ACIN1. |
| Laminin complex | A large, extracellular glycoprotein complex composed of three different polypeptide chains, alpha, beta and gamma. Provides an integral part of the structural scaffolding of basement membranes. |
| Cytosolic small ribosomal subunit | The small subunit of a ribosome located in the cytosol. |
| Type I interferon receptor complex | |
| Mitochondrial outer membrane translocase complex | A large complex of the mitochondrial outer membrane that mediates transport of proteins into all mitochondrial compartments. |
| Ribosomal subunit | Either of the two subunits of a ribosome: the ribosomal large subunit or the ribosomal small subunit. |
| XPC complex | A nucleotide-excision repair complex that is involved in damage sensing during global genome nucleotide excision repair (GG-NER). It is part of the pre-incision (or initial recognition) complex bound to sites of DNA damage. In human, it is composed of XPC, RAD23B and CETN2. |
| GABA-A receptor complex | A protein complex which is capable of GABA-A receptor activity. In human, it is usually composed of either two alpha, two beta and one gamma chain of the GABA-A receptor subunits or 5 chains of the GABA-A receptor subunits rho1-3 (formally known as GABA-C receptor). |
| Integral component of organelle membrane | The component of the organelle membrane consisting of the gene products that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| DNA polymerase III complex | The DNA polymerase III holoenzyme is a complex that contains 10 different types of subunits. These subunits are organized into 3 functionally essential sub-assemblies: the pol III core, the beta sliding clamp processivity factor and the clamp-loading complex. The pol III core carries out the polymerase and the 3'-5' exonuclease proofreading activities. The polymerase is tethered to the template via the sliding clamp processivity factor. The clamp-loading complex assembles the beta processivity factor onto the primer template and plays a central role in the organization and communication at the replication fork. |
| Ribonuclease H2 complex | A protein complex that possesses ribonuclease H activity, in which the catalytic subunit is a member of the RNase H2 (or HII) class. For example, in Saccharomyces the complex contains Rnh201p, Rnh202p and Rnh203p. |
| BAT3 complex | An ER membrane insertion complex that acts by facilitating tail-anchored protein capture by ASNA1/TRC40. In mammals the complex contains Bat3, TRC35 and Ubl4A. |
| UFD1-NPL4 complex | |
| Golgi apparatus subcompartment | |
| Cargo receptor complex | |
| Vesicle tethering complex | |
| Mis6-Sim4 complex | A protein complex that forms part of the inner centromere, which is involved in the loading of the centromeric histone h3 variant CENP-A onto centromeres and in centromere specific heterochromatin formation. The complex contains about 12 proteins, of which two are known as Mis6 and Sim4 in S. pombe and CENP-I and CENP-H in human. |
| SCAR complex | A heterotetrameric complex that includes orthologues of human PIR121, Nap125 and HSPC300 and regulates actin polymerization and/or depolymerization through small GTPase mediated signal transduction. |
| Phosphatidylinositol 3-kinase complex, class IB | A class I phosphatidylinositol 3-kinase complex that possesses 1-phosphatidylinositol-4-phosphate 3-kinase activity; comprises a catalytic class IB phosphoinositide 3-kinase (PI3K) subunit and an associated regulatory subunit that is larger than, and unrelated to, the p85 proteins present in class IA complexes. Class IB PI3Ks are stimulated by G-proteins and do not interact with the SH2-domain containing adaptors that bind to Class IA PI3Ks. |
| MTREC complex | |
| Membrane fusion priming complex | |
| tRNA (m7G46) methyltransferase complex | |
| Contractile ring | A cytoskeletal structure composed of filamentous protein that forms beneath the membrane of many cells or organelles, in the plane of cell or organelle division. Ring contraction is associated with centripetal growth of the membrane that divides the cytoplasm of the two daughter cells or organelles. |
| Brush border membrane | The portion of the plasma membrane surrounding the brush border. |
| Distal axon | |
| Lsm2-8 complex | |
| Methylosome | A large (20 S) protein complex that possesses protein arginine methyltransferase activity and modifies specific arginines to dimethylarginines in the arginine- and glycine-rich domains of several spliceosomal Sm proteins, thereby targeting these proteins to the survival of motor neurons (SMN) complex for assembly into small nuclear ribonucleoprotein (snRNP) core particles. Proteins found in the methylosome include the methyltransferase JBP1 (PRMT5), pICln (CLNS1A), MEP50 (WDR77), and unmethylated forms of SM proteins that have RG domains. |
| RNA polymerase IV complex | |
| Glycocalyx | A viscous, carbohydrate rich layer at the outermost periphery of a cell. |
| Myosin X complex | |
| NADH dehydrogenase complex | An integral membrane complex that possesses NADH oxidoreductase activity. The complex is one of the components of the electron transport chain. It catalyzes the transfer of a pair of electrons from NADH to a quinone. |
| Giant axon | Extremely large, unmyelinated axon found in invertebrates. Has high conduction speeds and is usually involved in panic or escape responses. |
| Set3 complex | A histone deacetylase complex that is involved in transcriptional regulation. In S. cerevisiae, this complex consists of Set3p, Snt1p, Hos4p, Sif2p, Cpr1p, Hos2p, and Hst1p. |
| GABA receptor complex | A protein complex which is capable of GABA receptor activity. Upon binding of gamma-aminobutyric acid (GABA) it transmits the signal from one side of the membrane to the other to initiate a change in cell activity. Major inhibitory receptor in vertebrate brain. Also found in other vertebrate tissues, invertebrates and possibly in plants. Effective benzodiazepine receptor. |
| sno(s)RNA-containing ribonucleoprotein complex | |
| Smc5-Smc6 complex | A conserved complex that contains a heterodimer of SMC proteins (Smc5p and Smc6p, or homologs thereof) and several other proteins, and is involved in DNA repair and maintaining cell cycle arrest following DNA damage. In S. cerevisiae, this is an octameric complex called Mms21-Smc5-Smc6 complex, with at least five of its subunits conserved in fission yeast and humans. |
| GATOR2 complex | |
| Nuclear membrane protein complex | |
| Septin complex | A protein complex containing septins. Typically, these complexes contain multiple septins and are oligomeric. |
| Syntrophin complex | A protein complex that includes alpha-, beta1-, beta2-syntrophins and syntrophin-like proteins; the syntrophin complex binds to the second half of the carboxy-terminal domain of dystrophin; also associates with neuronal nitric oxide synthase. |
| Z granule | |
| Integrin alpha2-beta1 complex | An integrin complex that comprises one alpha2 subunit and one beta1 subunit. |
| Myosin phosphatase complex | An enzyme complex that catalyzes the removal of the phosphate group from phosphomyosin. |
| 6-phosphofructokinase complex | A protein complex that possesses 6-phosphofructokinase activity; homodimeric, homooctameric, and allosteric homotetrameric forms are known. |
| Inner dynein arm | Inner arm structure present on the outer doublet microtubules of ciliary and flagellar axonemes. The structure of inner dynein arms is complex and may vary within the axoneme. Inner and outer dynein arms have different functions in the generation of microtubule-based motility. |
| Subrhabdomeral cisterna | A membrane-bounded compartment that is found at the base of the rhabdomere and contains stored calcium, InsP3 receptors and smooth endoplasmic reticulum Ca2+-ATPase. |
| F-actin capping protein complex | A heterodimer consisting of alpha and beta subunits that binds to and caps the barbed ends of actin filaments, thereby regulating the polymerization of actin monomers but not severing actin filaments. |
| GID complex | A protein complex with ubiquitin ligase activity that is involved in proteasomal degradation of fructose-1,6-bisphosphatase (FBPase) and phosphoenolpyruvate carboxykinase during the transition from gluconeogenic to glycolytic growth conditions. In S. cerevisiae, the GID (Glucose Induced degradation Deficient) complex consists of Vid30p, Rmd5p, Vid24p, Vid28p, Gid7p, Gid8p, and Fyv10p. |
| Transcription preinitiation complex | |
| DRM complex | A transcriptional repressor complex that contains the lin-9, lin-35, lin-37, lin-52, lin-53, lin-5is involved in 4-, dpl-1 and efl-1 proteins, and is involved in cell fate specification. |
| PCSK9-LDLR complex | |
| Synaptic membrane | A specialized area of membrane on either the presynaptic or the postsynaptic side of a synapse, the junction between a nerve fiber of one neuron and another neuron or muscle fiber or glial cell. |
| clathrin-coated vesicle | A vesicle with a coat formed of clathrin connected to the membrane via one of the clathrin adaptor complexes. |
| Integrin alphav-beta3 complex | An integrin complex that comprises one alphav subunit and one beta3 subunit. |
| RQC complex | |
| Secretory vesicle | |
| Paraspeckles | Discrete subnuclear bodies in the interchromatin nucleoplasmic space, often located adjacent to nuclear specks. 10-20 paraspeckles are typically found in human cell nuclei. |
| Axon initial segment | Portion of the axon proximal to the neuronal cell body, at the level of the axon hillock. The action potentials that propagate along the axon are generated at the level of this initial segment. |
| Isocitrate dehydrogenase complex (NAD+) | |
| Mitochondrial isocitrate dehydrogenase complex (NAD+) | |
| Rad51B-Rad51C-Rad51D-XRCC2 complex | A DNA recombinase mediator complex that contains the Rad51 paralogs RAD51B, RAD51C, RAD51D, and XRCC2, or orthologs thereof. |
| interleukin-2 receptor complex | A protein complex that binds interleukin-2; comprises alpha, beta, and gamma subunits. |
| Cytosolic ribosome | A ribosome located in the cytosol. |
| Photoreceptor cell cilium | |
| oncostatin-M receptor complex | A heterodimeric receptor for the cytokine oncostatin-M (OSM). In humans the receptor complex is made up of the gene products gp130 and OSMR-beta. |
| Egg coat | A specialized extracellular matrix that surrounds the ovum of animals. The egg coat provides structural support and can play an essential role in oogenesis, fertilization and early development. |
| Glial cytoplasmic inclusion | Non-membrane-bound cytoplasmic inclusions composed of 10-40 nm granule-coated fibrils. These inclusions have an abnormal accumulation of alpha-synuclein protein and are found in association with multiple system atrophy. |
| Nuclear membrane microtubule tethering complex | |
| Meiotic nuclear membrane microtubule tethering complex | |
| Myelin sheath | The cylindrical covering on the axons of some neurons; it consists of concentric layers of myelin, formed in the peripheral nervous system by the plasma membrane of Schwann cells, and in the central nervous system by oligodendrocytes. It is interrupted at intervals along its length by gaps known as nodes of Ranvier. Myelin is an electrical insulator that serves to speed the conduction of nerve impulses. |
| RNA polymerase II transcription repressor complex | A protein complex, located in the nucleus, that possesses activity that prevents or downregulates transcription from a RNA polymerase II promoter. |
| TRAMP complex | A multiprotein complex having distributive polyadenylation activity of a variety of RNA substrates including hypomodified and incorrectly folded tRNAs, pre-snRNAs, pre-snoRNAs, incorrectly spliced or processed pre-mRNAs, cryptic unstable transcripts (CUTs), pre-rRNAs and rRNA fragments released as part of rRNA processing. In S. cerevisiae, the complex consists of either Pap2 (also known as Trf4) or Trf5, Air1 or Air2, and Mtr4, and is involved in RNA 3'-end processing and in RNA surveillance and quality control. |
| Microtubule end | |
| trans-Golgi network | The network of interconnected tubular and cisternal structures located within the Golgi apparatus on the side distal to the endoplasmic reticulum, from which secretory vesicles emerge. The trans-Golgi network is important in the later stages of protein secretion where it is thought to play a key role in the sorting and targeting of secreted proteins to the correct destination. |
| Nuclear replication fork | The Y-shaped region of a nuclear replicating DNA molecule, resulting from the separation of the DNA strands and in which the synthesis of new strands takes place. Also includes associated protein complexes. |
| Outer mitochondrial membrane protein complex | |
| Spermatoproteasome complex | A proteasome specifically found in mammalian testis. Contains the proteasome activator PA200 in the regulatory particle, and beta1i, beta2i, beta5i and/or alpha4s in the core (20S) subunit. Beta1i, beta2i and beta5i are inducible catalytic subunits, closely related to beta1, beta2 and beta5. Alpha4s is a sperm-specific 20S subunit, but unlike other alternative 20S subunits alpha4s lies in the outer alpha-ring and lacks catalytic activity. |
| Signal recognition particle, endoplasmic reticulum targeting | A ribonucleoprotein particle of 325 kDa composed of a 7S (300 nucleotide) RNA molecule and a complex of six different polypeptides. This binds both to the N-terminal signal peptide for proteins destined for the endoplasmic reticulum as they emerge from the large ribosomal subunit and also to the ribosome. This binding arrests further translation thereby preventing the proteins from being released into the cytosol. The SRP-ribosome complex then diffuses to the endoplasmic reticulum where it is bound to the signal recognition particle receptor, which allows resumption of protein synthesis and facilitates the passage of the growing polypeptide chain through the translocon. Through a process involving GTP hydrolysis, the SRP-SRP receptor complex dissociates and SRP returns to the cytosol. Of the six polypeptides of SRP the 54 kDa subunit (SRP54) is the central player. It contains an N-terminal GTPase domain and a C-terminal domain that binds directly to the signal peptide and the SRP RNA. Examples of this component are found in Mus musculus, Saccharomyces cerevisiae and Arabidopsis thaliana. |
| Integrin alpha8-beta1 complex | An integrin complex that comprises one alpha8 subunit and one beta1 subunit. |
| Cluster of actin-based cell projections | |
| Extrinsic component of plasma membrane | The component of a plasma membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| BLOC complex | Any of several protein complexes required for the biogenesis of specialized organelles of the endosomal-lysosomal system, such as melanosomes, platelet dense granules, and other related organelles; acronym for biogenesis of lysosomal-related organelles complex. |
| Fc-gamma receptor I complex | A protein complex composed of an Fc-gamma RI alpha chain and an Fc-epsilon RI gamma chain dimer with or without additional signaling components. The complex functions primarily as an activating receptor for IgG. |
| CARD8 inflammasome complex | |
| Sec61 translocon complex | A translocon complex that contains a core heterotrimer of conserved alpha, beta and gamma subunits, and may contain additional proteins (translocon-associated proteins or TRAPs); in budding yeast the core proteins are Sec61p, Sbh1p, and Sss1p. The Sec61 translocon complex functions in cotranslational and posttranslational translocation events. |
| Integrin alpha1-beta1 complex | An integrin complex that comprises one alpha1 subunit and one beta1 subunit. |
| Nuclear replisome | A multi-component enzymatic machine at the nuclear replication fork, which mediates DNA replication. Includes DNA primase, one or more DNA polymerases, DNA helicases, and other proteins. |
| Kinesin II complex | A complex consisting of two distinct motor subunits that form a heterodimer complexed with a third non-motor accessory subunit, the kinesin associated protein or KAP; the KIF3 heterodimer interacts via its C-terminal portion with KAP, which is thought to regulate the binding of the motor to cargo membranes. |
| Ciliary membrane | The portion of the plasma membrane surrounding a cilium. |
| Vacuolar membrane | The lipid bilayer surrounding the vacuole and separating its contents from the cytoplasm of the cell. |
| SOSS complex | A protein complex that functions downstream of the MRN complex to promote DNA repair and the G2/M checkpoint. The SOSS complex associates with single-stranded DNA at DNA lesions and is composed of SOSS-B (SOSS-B1/OBFC2B or SOSS-B2/OBFC2A), SOSS-A/INTS3 and SOSS-C/C9orf80. |
| Compact myelin | The portion of the myelin sheath in which layers of cell membrane are tightly juxtaposed, completely excluding cytoplasm. The juxtaposed cytoplasmic surfaces form the major dense line, while the juxtaposed extracellular surfaces form the interperiod line visible in electron micrographs. |
| phospholipid-translocating ATPase complex | |
| Crystalloid | A transient, cytoplasmic organelle found in Plasmodium species that resembles a cytoplasmic inclusion body and whose function is poorly understood. Crystalloids form in ookinetes and disappear after ookinete-to-oocyst transformation. |
| BRCA1-C complex | A protein complex that contains the BRCA1-BARD1 heterodimer, CtIP and Mre11/Rad50/NBS1 (M/R/N) complex, and binds to DNA at DNA damage sites. BRCA1-C binding ta damaged DNA is required for DNA damage-induced Chk1 phosphorylation and the G2/M transition checkpoint. |
| Intrinsic component of organelle membrane | The component of the organelle membrane consisting of the gene products that have some covalently attached part (e.g. peptide sequence or GPI anchor) which spans or is embedded in one or both leaflets of the membrane. |
| Nuclear envelope | The double lipid bilayer enclosing the nucleus and separating its contents from the rest of the cytoplasm; includes the intermembrane space, a gap of width 20-40 nm (also called the perinuclear space). |
| Dynein complex | Any of several large complexes that contain two or three dynein heavy chains and several light chains, and have microtubule motor activity. |
| tRNA-intron endonuclease complex | A protein complex that catalyzes the endonucleolytic cleavage of pre-tRNA, producing 5'-hydroxyl and 2',3'-cyclic phosphate termini, and specifically removing the intron. |
| H4 histone acetyltransferase complex | A protein complex which is capable of H4 histone acetyltransferase activity. |
| Microtubule plus-end | The growing (plus) end of a microtubule. In vitro, microtubules polymerize more quickly at the plus end than at the minus end. In vivo, microtubule growth occurs only at the plus end, and the plus end switches between periods of growth and shortening, a behavior known as dynamic instability. |
| Dystrobrevin complex | A protein complex comprising alpha- and beta-dystrobrevin; forms part of the dystrophin glycoprotein complex. |
| Multimerin complex | |
| WASH complex | A protein complex that localizes at the surface of endosomes, where it recruits and activates the Arp2/3 complex to induce actin polymerization. In human, the WASH complex is composed of F-actin-capping protein subunits alpha and beta, WASH1, FAM21, KIAA1033, KIAA0196 and CCDC53. |
| Cytolytic granule | A specialized secretory lysosome that is present in cells with cytolytic capability such as cytotoxic T lymphocytes and natural killer cells. Cytolytic granules mediate the storage and regulated excretion of lytic molecules for killing of target cells. |
| Spindle pole | Either of the ends of a spindle, where spindle microtubules are organized; usually contains a microtubule organizing center and accessory molecules, spindle microtubules and astral microtubules. |
| Protein phosphatase 4 complex | The complex formed by the catalytic subunit of protein phosphatase 4 plus a regulatory subunit. |
| interleukin-15 receptor complex | |
| B cell receptor complex | An immunoglobulin complex that is present in the plasma membrane of B cells and that in its canonical form is composed of two identical immunoglobulin heavy chains and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| DNA recombinase mediator complex | A protein complex containing accessory proteins which bind a recombinase (e.g. Rad51) and bind single-stranded DNA (ssDNA), and promote nucleation of the recombinase onto ssDNA. |
| Ciliary plasm | |
| Axoneme | The bundle of microtubules and associated proteins that forms the core of cilia (also called flagella) in eukaryotic cells and is responsible for their movements. |
| Matrilin complex | |
| Calcineurin complex | A heterodimeric calcium ion and calmodulin dependent protein phosphatase composed of catalytic and regulatory subunits; the regulatory subunit is very similar in sequence to calmodulin. |
| Integral component of mitochondrial membrane | The component of the mitochondrial membrane consisting of the gene products that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Integral component of mitochondrial inner membrane | The component of the mitochondrial inner membrane consisting of the gene products that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| nBAF complex | A SWI/SNF-type complex that is found in post-mitotic neurons, and in human contains actin and proteins encoded by the ARID1A/BAF250A or ARID1B/BAF250B, SMARCD1/BAF60A, SMARCD3/BAF60C, SMARCA2/BRM/BAF190B, SMARCA4/BRG1/BAF190A, SMARCB1/BAF47, SMARCC1/BAF155, SMARCE1/BAF57, SMARCC2/BAF170, DPF1/BAF45B, DPF3/BAF45C, ACTL6B/BAF53B genes. The nBAF complex along with CREST plays a role regulating the activity of genes essential for dendrite growth. |
| Amylin receptor complex | |
| Phosphatidylinositol 3-kinase complex, class II | |
| Flotillin complex | A protein complex that contains flotillin-1 and flotillin-2, and may contain associated proteins. Flotillins associate into membrane microdomains resembling caveolae. |
| Outer dense fiber | Structure or material found in the flagella of mammalian sperm that surrounds each of the nine microtubule doublets, giving a 9 + 9 + 2 arrangement rather than the 9 + 2 pattern usually seen. These dense fibers are stiff and noncontractile. |
| Cortical granule | A secretory vesicle that is stored under the cell membrane of an egg. These vesicles fuse with the egg plasma membrane as part of egg activation and are part of the block to polyspermy. |
| Insulin receptor complex | A disulfide-bonded, heterotetrameric receptor complex. The alpha chains are entirely extracellular, while each beta chain has one transmembrane domain. The ligand binds to the alpha subunit extracellular domain and the kinase is associated with the beta subunit intracellular domain. |
| Glycoprotein network | An extracellular matrix part that consists of cross-linked glycoproteins. |
| non-motile cilium | |
| Cyclin B1-CDK1 complex | A protein complex consisting of cyclin B1 and cyclin-dependent kinase 1 (CDK1). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Nuclear RNA export factor complex | A protein complex that contains two proteins (know in several organisms, including Drosophila, as NXF1 and NXF2) and is required for the export of the majority of mRNAs from the nucleus to the cytoplasm; localized in the nucleoplasm and at both the nucleoplasmic and cytoplasmic faces of the nuclear pore complex; shuttles between the nucleus and the cytoplasm. |
| Proteasome regulatory particle | A multisubunit complex, which caps one or both ends of the proteasome core complex. This complex recognizes and unfolds ubiquitinated proteins, and translocates them to the proteasome core complex. |
| Type VI protein secretion system complex | A complex of proteins that permits the transfer of proteins into the extracellular milieu or directly into host cells via the type VI secretion system. Proteins secreted by this complex do not require an N-terminal signal sequence. |
| Mitotic spindle | A spindle that forms as part of mitosis. Mitotic and meiotic spindles contain distinctive complements of proteins associated with microtubules. |
| Endoplasmic reticulum-Golgi intermediate compartment | A complex system of membrane-bounded compartments located between endoplasmic reticulum (ER) and the Golgi complex, with a distinctive membrane protein composition; involved in ER-to-Golgi transport. |
| Cortical microtubule cytoskeleton | The portion of the microtubule cytoskeleton that lies just beneath the plasma membrane. |
| Telomerase holoenzyme complex | Telomerase is a ribonucleoprotein enzyme complex, with a minimal catalytic core composed of a catalytic reverse transcriptase subunit and an RNA subunit that provides the template for telomeric DNA addition. In vivo, the holoenzyme complex often contains additional subunits. |
| voltage-gated potassium channel complex | A protein complex that forms a transmembrane channel through which potassium ions may cross a cell membrane in response to changes in membrane potential. |
| Mitochondrial tricarboxylic acid cycle enzyme complex | Any of the heteromeric enzymes, located in the mitochondrion, that act in the tricarboxylic acid (TCA) cycle. |
| Keratohyalin granule | A cytoplasmic, non-membrane bound granule of, at least, keratinocyte. Associated to keratin intermediate filaments and partially crosslinked to the cell envelope. |
| glycine-tRNA ligase complex | |
| FAR/SIN/STRIPAK complex | A conserved protein phosphatase type 2A complex which contains a protein phosphatase type 2A, a protein phosphatase regulatory subunit, a striatin, an FHA domain protein and other subunits (at least six proteins). In fission yeast this complex negatively regulate the septation initiation network at the spindle pole body. |
| Nuclear body | Extra-nucleolar nuclear domains usually visualized by confocal microscopy and fluorescent antibodies to specific proteins. |
| Microtubule organizing center attachment site | A region of the nuclear envelope to which a microtubule organizing center (MTOC) attaches; protein complexes embedded in the nuclear envelope mediate direct or indirect linkages between the microtubule cytoskeleton and the nuclear envelope. |
| Phosphopantothenoylcysteine decarboxylase complex | |
| Protein body | A membrane-bounded plant organelle found in the developing endosperm, contains storage proteins. |
| 9+2 motile cilium | |
| Transcription factor TFIIIC complex | A heterotrimeric transcription factor complex that is involved in regulating transcription from RNA polymerase III (Pol III) promoters. TFIIIC contains three conserved subunits that associate with the proximal Pol III promoter element, and additional subunits that associate with sequence elements downstream of the promoter and are more diverged among species. It also functions as a boundary element to partition genome content into distinct domains outside Pol III promoter regions. |
| Ribonuclease P complex | A ribonucleoprotein complex that catalyzes cleavage of the leader sequence of precursor tRNAs (pre-tRNAs), generating the mature 5' end of tRNAs. |
| Tectum | |
| Phosphatidylinositol 3-kinase complex, class I | A phosphatidylinositol 3-kinase complex that contains a catalytic and a regulatory subunit of a phosphatidylinositol 3-kinase (PI3K) enzyme, plus one or more adaptor proteins. Class I PI3Ks phosphorylate phosphatidylinositol [PI], phosphatidylinositol-4-phosphate [PI(4)P] and phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], and are divided into subclasses A and B according to the type of adaptor subunit with which they associate. The class I PI3K subfamily of genes comprises members in vertebrates, worm and fly, but none in yeast. |
| Nuclear RNA-directed RNA polymerase complex | A complex required for RNAi mediated heterochromatin assembly. In S. pombe this contains RNA-directed RNA polymerase, a putative helicase and a protein containing a pap25 associated domain. |
| Biofilm matrix | A structure lying external to bacterial cells. A biofilm is an aggregate of surface-associated bacteria, and the biofilm matrix is the envelope of polymeric substances that surrounds the bacteria. |
| Respiratory chain complex IV | A part of the respiratory chain, containing the 13 polypeptide subunits of cytochrome c oxidase, including cytochrome a and cytochrome a3. Catalyzes the oxidation of reduced cytochrome c by dioxygen (O2). |
| Postsynaptic membrane | A specialized area of membrane facing the presynaptic membrane on the tip of the nerve ending and separated from it by a minute cleft (the synaptic cleft). Neurotransmitters across the synaptic cleft and transmit the signal to the postsynaptic membrane. |
| Cyclin D1-CDK4 complex | A protein complex consisting of cyclin D1 and cyclin-dependent kinase 4 (CDK4). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Chaperone complex | |
| interleukin-7 receptor complex | |
| Perisynaptic extracellular matrix | |
| Exoneme | A dense granule-like organelle of the apical complex of merozoites, released into the parasitophorous vacuole, mediating protease-dependent rupture and parasite exit from the infected erythrocyte. |
| SAM complex | |
| synapse-associated extracellular matrix | |
| Ciliary transition zone | A region of the cilium between the basal body and proximal segment that is characterized by Y-shaped assemblages that connect axonemal microtubules to the ciliary membrane. The ciliary transition zone appears to function as a gate that controls ciliary membrane composition. |
| B800-820 antenna complex | |
| Growth cone | The migrating motile tip of a growing nerve cell axon or dendrite. |
| interleukin-6 receptor complex | A hexameric protein complex consisting of two molecules each of interleukin-6, interleukin-6 receptor alpha chain, and gp-130. |
| Apoptotic body | A fragment containing parts of a dying cell. Apoptotic bodies can be formed during the execution phase of the apoptotic process, when the cell's cytoskeleton breaks up and causes the membrane to bulge outward. These bulges may separate from the cell, taking a portion of cytoplasm with them, to become apoptotic bodies. These are then engulfed by phagocytic cells, and their components recycled. |
| LinE complex | |
| Preribosome | Any complex of pre-rRNAs, ribosomal proteins, and associated proteins formed during ribosome biogenesis. |
| Aggresome | An inclusion body formed by dynein-dependent retrograde transport of an aggregated protein on microtubules. |
| Heparanase complex | |
| B800-850 antenna complex | Protein-pigment complex that absorbs light at 800 and 850 nm; is peripherally associated to the bacterial reaction center; transfers excitation energy to the B875 antenna complex. |
| Septin ring | A tight ring-shaped structure that forms in the division plane at the site of cytokinesis; composed of members of the conserved family of filament-forming proteins called septins as well as septin-associated proteins. This type of septin structure is observed at the bud neck of budding fungal cells, at the site of cell division in animal cells, at the junction between the mother cell and a pseudohyphal projection, and also within hyphae of filamentous fungi at sites where a septum will form. |
| Las1 complex | |
| Extrinsic component of membrane | The component of a membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| Replisome | A multi-component enzymatic machine at the replication fork which mediates DNA replication. Includes DNA primase, one or more DNA polymerases, DNA helicases, and other proteins. |
| TIM22 mitochondrial import inner membrane insertion complex | |
| Filopodium | Thin, stiff protrusion extended by the leading edge of a motile cell such as a crawling fibroblast or amoeba, or an axonal or dendritic growth cone, or a dendritic shaft. |
| Sin3-type complex | Any of a number of evolutionarily conserved histone deacetylase complexes (HDACs) containing a core consisting of a paired amphipathic helix motif protein (e.g. Sin3p in S. cerevisiae, Pst1 in S. pombe or Sin3A in mammals) at least one class I histone deacetylase (e.g. Rpd3p in S. cerevisiae, Clr6 in S. pombe, or HDAC1 and HDAC2 in mammals), and at least one WD40 repeat protein (e.g. Ume1p in S. cerevisiae, Prw1 in S. pombe, or RbAp46 and RbAp48 in mammals). These complexes also contain a variable number of other proteins that direct histone binding, DNA binding, or add other functionality to the complex. |
| beta-catenin-TCF complex | |
| I band | A region of a sarcomere that appears as a light band on each side of the Z disc, comprising a region of the sarcomere where thin (actin) filaments are not overlapped by thick (myosin) filaments; contains actin, troponin, and tropomyosin; each sarcomere includes half of an I band at each end. |
| Cul5-RING ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul5 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by an elongin-BC adaptor and a SOCS/BC box protein. |
| Golgi apparatus | A compound membranous cytoplasmic organelle of eukaryotic cells, consisting of flattened, ribosome-free vesicles arranged in a more or less regular stack. The Golgi apparatus differs from the endoplasmic reticulum in often having slightly thicker membranes, appearing in sections as a characteristic shallow semicircle so that the convex side (cis or entry face) abuts the endoplasmic reticulum, secretory vesicles emerging from the concave side (trans or exit face). In vertebrate cells there is usually one such organelle, while in invertebrates and plants, where they are known usually as dictyosomes, there may be several scattered in the cytoplasm. The Golgi apparatus processes proteins produced on the ribosomes of the rough endoplasmic reticulum; such processing includes modification of the core oligosaccharides of glycoproteins, and the sorting and packaging of proteins for transport to a variety of cellular locations. Three different regions of the Golgi are now recognized both in terms of structure and function: cis, in the vicinity of the cis face, trans, in the vicinity of the trans face, and medial, lying between the cis and trans regions. |
| Euchromatin | A dispersed and relatively uncompacted form of chromatin. |
| single-stranded DNA-binding protein complex | |
| Histone acetyltransferase complex | A protein complex that possesses histone acetyltransferase activity. |
| Platelet alpha granule | A secretory organelle found in blood platelets, which is unique in that it exhibits further compartmentalization and acquires its protein content via two distinct mechanisms: (1) biosynthesis predominantly at the megakaryocyte (MK) level (with some vestigial platelet synthesis) (e.g. platelet factor 4) and (2) endocytosis and pinocytosis at both the MK and circulating platelet levels (e.g. fibrinogen (Fg) and IgG). |
| Vacuolar transporter chaperone complex | A protein complex that contains four related proteins that have been implicated in several membrane-related processes, such as sorting of H+-translocating ATPases, endocytosis, ER-Golgi trafficking, vacuole fusion, vacuolar polyphosphate homeostasis and the microautophagic scission of vesicles into the vacuolar lumen. The complex is enriched at the vacuolar membrane, but also found in other cellular compartments, including the ER and the cell periphery. In Saccharomyces, the subunits are Vtc1p, Vtc2p, Vtc3p and Vtc4p. |
| EARP complex | |
| COPI-coated vesicle | A vesicle with a coat formed of the COPI coat complex proteins. COPI-coated vesicles are found associated with Golgi membranes at steady state, are involved in Golgi to endoplasmic reticulum (retrograde) vesicle transport, and possibly also in intra-Golgi transport. |
| alpha-beta T cell receptor complex | A T cell receptor complex in which the TCR heterodimer comprises alpha and beta chains, associated with the CD3 complex; recognizes a complex consisting of an antigen-derived peptide bound to a class I or class II MHC protein. |
| Cell division site | The eventual plane of cell division (also known as cell cleavage or cytokinesis) in a dividing cell. In Eukaryotes, the cleavage apparatus, composed of septin structures and the actomyosin contractile ring, forms along this plane, and the mitotic, or meiotic, spindle is aligned perpendicular to the division plane. In bacteria, the cell division site is generally located at mid-cell and is the site at which the cytoskeletal structure, the Z-ring, assembles. |
| Transcription export complex 2 | A protein complex that couples SAGA-dependent gene expression to mRNA export at the inner side of the nuclear pore complex (NPC). The TREX-2 complex is tethered to the inner side of the NPC via the nucleoporins Nup1 and Nup60; in S. cerevisiae it contains Sac3p, Thp1p, Sus1p and Cdc31p. |
| Mitochondrial respirasome | |
| Plasma membrane bounded cell projection cytoplasm | |
| Shu complex | A protein complex involved in error-free DNA post-replication repair (PRR). In Saccharomyces cerevisiae the complex contains Csm2p, Psy3p, Shu1p, and Shu2p. |
| P granule | A small cytoplasmic, non-membranous RNA/protein complex aggregates in the primordial germ cells of many higher eukaryotes. |
| Silver ion transmembrane transporter complex | |
| Cus cation efflux complex | |
| Coated vesicle | Small membrane-bounded organelle formed by pinching off of a coated region of membrane. Some coats are made of clathrin, whereas others are made from other proteins. |
| Copper ion transmembrane transporter complex | |
| Activin receptor complex | A protein complex that acts as an activin receptor. Heterodimeric activin receptors, comprising one Type I activin receptor and one Type II receptor polypeptide, and heterotrimeric receptors have been observed. |
| Autophagosome membrane | |
| Amylin receptor complex 1 | |
| glycerol-3-phosphate dehydrogenase complex | An enzyme complex that catalyzes the dehydrogenation of sn-glycerol 3-phosphate to form glycerone phosphate. |
| RNA polymerase II, core complex | |
| Polysome | A multiribosomal structure representing a linear array of ribosomes held together by messenger RNA. They represent the active complexes in cellular protein synthesis and are able to incorporate amino acids into polypeptides both in vivo and in vitro. |
| t-UTP complex | A protein complex that forms a subcomplex of the 90S preribosome and is required for the subsequent assembly of the rest of the preribosome. In S. cerevisiae, it is composed of Utp5p, Utp4p, Nan1p, Utp8p, Utp9p, Utp10 and Utp15p. |
| Proximal dendrite | |
| Midbody | A thin cytoplasmic bridge formed between daughter cells at the end of cytokinesis. The midbody forms where the contractile ring constricts, and may persist for some time before finally breaking to complete cytokinesis. |
| Nuclear membrane | Either of the lipid bilayers that surround the nucleus and form the nuclear envelope; excludes the intermembrane space. |
| Perineuronal net | A dense extracellular matrix (ECM) structure that forms around many neuronal cell bodies and dendrites late in development and is responsible for synaptic stabilization in the adult brain. |
| Z disc | Platelike region of a muscle sarcomere to which the plus ends of actin filaments are attached. |
| Rhabdomere | The specialized microvilli-containing organelle on the apical surfaces of a photoreceptor cell containing the visual pigment rhodopsin and most of the proteins involved in phototransduction. |
| Heterotrimeric G-protein complex | Any of a family of heterotrimeric GTP-binding and hydrolyzing proteins; they belong to a superfamily of GTPases that includes monomeric proteins such as EF-Tu and RAS. Heterotrimeric G-proteins consist of three subunits; the alpha subunit contains the guanine nucleotide binding site and possesses GTPase activity; the beta and gamma subunits are tightly associated and function as a beta-gamma heterodimer; extrinsic plasma membrane proteins (cytoplasmic face) that function as a complex to transduce signals from G-protein coupled receptors to an effector protein. |
| DNA topoisomerase type II (double strand cut, ATP-hydrolyzing) complex | |
| gamma-delta T cell receptor complex | A T cell receptor complex in which the TCR heterodimer comprises gamma and delta chains, associated with the CD3 complex; recognizes antigen directly, without a requirement for processing and presentation by an MHC protein. |
| SAGA-type complex | A histone acetyltransferase complex that acetylates nucleosomal H3 and H2B and is required for the expression of a subset of Pol II-transcribed genes. The budding yeast complex includes the acetyltransferase Gcn5p, several proteins of the Spt and Ada families, and several TBP-associate proteins (TAFs); analogous complexes in other species have analogous compositions, and usually contain homologs of the yeast proteins. |
| Mutator focus | |
| Extrinsic component of cytoplasmic side of plasma membrane | The component of a plasma membrane consisting of gene products and protein complexes that are loosely bound to its cytoplasmic surface, but not integrated into the hydrophobic region. |
| Chloride channel complex | An ion channel complex through which chloride ions pass. |
| Site of polarized growth | Any part of a cell where non-isotropic growth takes place. |
| Fc-alpha receptor I complex | A protein complex composed of an Fc-alpha R alpha chain and an Fc-epsilon RI gamma chain dimer with or without additional signaling components. The complex functions primarily as an activating receptor for IgA. |
| DBIRD complex | A protein complex that associates with mRNP particles and RNA polymerase II and is proposed to integrate transcript elongation with the regulation of alternative splicing. In humans it is composed of the proteins KIAA1967/DBC1 and ZNF326/ZIRD. |
| COPI vesicle coat | One of two multimeric complexes that forms a membrane vesicle coat. The mammalian COPI subunits are called alpha-, beta-, beta'-, gamma-, delta-, epsilon- and zeta-COP. Vesicles with COPI coats are found associated with Golgi membranes at steady state. |
| Holliday junction resolvase complex | A protein complex that mediates the conversion of a Holliday junction into two separate duplex DNA molecules; the complex includes a single- or multisubunit helicase that catalyzes the extension of heteroduplex DNA by branch migration and a nuclease that resolves the junction by nucleolytic cleavage. |
| Transcription export complex | The transcription export (TREX) complex couples transcription elongation by RNA polymerase II to mRNA export. The complex associates with the polymerase and travels with it along the length of the transcribed gene. TREX is composed of the THO transcription elongation complex as well as other proteins that couple THO to mRNA export proteins. The TREX complex is known to be found in a wide range of eukaryotes, including S. cerevisiae and metazoans. |
| COPI-coated vesicle membrane | The lipid bilayer surrounding a COPI-coated vesicle. |
| Cytoplasmic side of plasma membrane | The leaflet the plasma membrane that faces the cytoplasm and any proteins embedded or anchored in it or attached to its surface. |
| pi-body | A P granule that contains the PIWIL2-TDRD1 module, a set of proteins that act in the primary piRNA pathway. The pi-body corresponds to the cementing material between mitochondria found in gonocytes. |
| Isw1 complex | A protein complex that contains an Isw1 subunit from the ISWI-family of ATPases and acts to modify chromatin structure. |
| EMILIN complex | |
| Spindle pole body | The microtubule organizing center in fungi; functionally homologous to the animal cell centrosome. |
| MLL1/2 complex | A protein complex that can methylate lysine-4 of histone H3, and which contains either of the protein subunits MLL1 or MLL2 in human, or equivalent in other species. |
| L-type voltage-gated calcium channel complex | A type of voltage-dependent calcium channel responsible for excitation-contraction coupling of skeletal, smooth, and cardiac muscle. 'L' stands for 'long-lasting' referring to the length of activation. |
| Terminal loop | Portion of myelin-forming Schwann cell consisting of terminal cytoplasmic extensions adhered to the axon at the beginning and end of the myelin sheath. |
| Cytoplasmic side of membrane | The side of a membrane that faces the cytoplasm. |
| DNA gyrase complex | |
| Elongin complex | A transcription elongation factor complex that suppresses RNA polymerase II pausing, and may act by promoting proper alignment of the 3'-end of nascent transcripts with the polymerase catalytic site. Consists of a transcriptionally active Elongin A subunit (abut 100 kDa)and two smaller Elongin B (about 18 kDa) and Elongin C (about 15 kDa)subunits. |
| Myosin I complex | A myosin complex containing a class I myosin heavy chain and associated light chains; myosin I heavy chains are single-headed, possess tails of various lengths, and do not self-associate into bipolar filaments; myosin I complexes are involved in diverse processes related to membrane traffic and cell movement. |
| Larval serum protein complex | A multisubunit protein complex which, in Drosophila, is a heterohexamer of three subunits, alpha, beta and gamma. The complex is thought to store amino acids for synthesis of adult proteins. |
| U2-type spliceosomal complex | Any spliceosomal complex that forms during the splicing of a messenger RNA primary transcript to excise an intron that has canonical consensus sequences near the 5' and 3' ends. |
| CBF3 complex | A multisubunit protein complex that binds to centromeric DNA and initiates kinetochore assembly. In yeast, this complex consists of four subunits, namely Ctf13p, Skp1p, Cep3p and Cbf2p. |
| Protein kinase CK2 complex | A protein complex that possesses protein serine/threonine kinase activity, and contains two catalytic alpha subunits and two regulatory beta subunits. Protein kinase CK2 complexes are found in nearly every subcellular compartment, and can phosphorylate many protein substrates in addition to casein. |
| Mediator complex | A protein complex that interacts with the carboxy-terminal domain of the largest subunit of RNA polymerase II and plays an active role in transducing the signal from a transcription factor to the transcriptional machinery. The mediator complex is required for activation of transcription of most protein-coding genes, but can also act as a transcriptional corepressor. The Saccharomyces complex contains several identifiable subcomplexes: a head domain comprising Srb2, -4, and -5, Med6, -8, and -11, and Rox3 proteins; a middle domain comprising Med1, -4, and -7, Nut1 and -2, Cse2, Rgr1, Soh1, and Srb7 proteins; a tail consisting of Gal11p, Med2p, Pgd1p, and Sin4p; and a regulatory subcomplex comprising Ssn2, -3, and -8, and Srb8 proteins. Metazoan mediator complexes have similar modular structures and include homologs of yeast Srb and Med proteins. |
| Migrasome | |
| Sperm fibrous sheath | A cytoskeletal structure surrounding the axoneme and outer dense fibers of the sperm flagellum. Consists of two longitudinal columns connected by closely arrayed semicircular ribs that assemble from distal to proximal throughout spermiogenesis. The fibrous sheath probably influences the degree of flexibility, plane of flagellar motion, and the shape of the flagellar beat. |
| voltage-gated calcium channel complex | A protein complex that forms a transmembrane channel through which calcium ions may pass in response to changes in membrane potential. |
| Rhoptry | A large, club-shaped secretory organelle that forms part of the apical complex of an apicomplexan parasite, and consists of a bulbous body and a narrow electron-dense neck that extends through the conoid at the apical tip of the parasite. The rhoptry necks serve as ducts through which the contents of the rhoptries are secreted after attachment to the host has been completed and at the commencement of invasion. Rhoptry proteins function in the biogenesis and host organellar association of the parasitophorous vacuole. |
| Outer dynein arm docking complex | |
| MKS complex | |
| 3-methylcrotonyl-CoA carboxylase complex, mitochondrial | A heterodimeric complex having 3-methylcrotonyl-CoA carboxylase activity. The alpha subunit has a covalently bound biotin essential for the ATP-dependent carboxylation. The beta subunit possess carboxyltransferase activity which presumably is essential for binding to 3-methylcrotonyl-CoA. |
| GW body | |
| Myc-Max complex | A transcription factor complex that consists of a heterodimer of the bHLH-ZIP proteins Myc and Max. |
| GTPase complex | |
| Syp1 complex | |
| Ragulator complex | A protein complex that contains MAPKSP1 (MP1, Map2k1ip1), ROBLD3 (p14, Mapbpip), and C11orf59 (p18). The complex is anchored to lipid rafts in late endosome membranes via C11orf59, recruits mTORC1 to lysosomal membranes in amino acid signaling to mTORC1, and is also involved in ERK/MAPK signaling. |
| Motile cilium | A cilium which has a variable arrangement of axonemal microtubules, contains molecular motors, and beats with a characteristic whip-like pattern that promotes cell motility or transport of fluids and other cells across a cell surface. Motile cilia are typically found in multiple copies on epithelial cells that line the lumenal ducts of various tissues. Motile cilia may also function as sensory organelles. |
| Root hair | A long, thin projection from a root epidermal cell that contains F-actin and tubulin, and a cell wall. |
| Glutamatergic synapse | |
| RNA polymerase V complex | |
| A band | The dark-staining region of a sarcomere, in which myosin thick filaments are present; the center is traversed by the paler H zone, which in turn contains the M line. |
| guanyl-nucleotide exchange factor complex | A protein complex that stimulates the exchange of guanyl nucleotides associated with a GTPase. |
| alpha,alpha-trehalose-phosphate synthase complex (UDP-forming) | A protein complex that possesses alpha,alpha-trehalose-phosphate synthase (UDP-forming) and trehalose-phosphatase activities, and thus catalyzes two reactions in trehalose biosynthesis. In the complex identified in Saccharomyces, Tps1p has alpha,alpha-trehalose-phosphate synthase (UDP-forming) activity, Tps2p has trehalose 6-phosphate phosphatase activity; Tps3p is a regulatory subunit, and an additional subunit, Tsl1p, may be present. |
| CURI complex | A protein complex that is involved in the transcription of ribosomal genes. In Saccharomyces this complex consists of Ckb2p, Utp22p, Rrp7p and Ifh1p. |
| Dense core granule | Electron-dense organelle with a granular internal matrix; contains proteins destined to be secreted. |
| Lateral loop | Non-compact myelin located adjacent to the nodes of Ranvier in a myelin segment. These non-compact regions include cytoplasm from the cell responsible for synthesizing the myelin. Lateral loops are found in the paranodal region adjacent to the nodes of Ranvier, while Schmidt-Lantermann clefts are analogous structures found within the compact myelin internode. |
| CHRAC | An ISWI complex that contains an ATPase subunit of the ISWI family (SNF2H in mammals, Isw2 in S. cerevisiae), an ACF1 homolog, and additional small histone fold subunits (generally two of these, but Xenopus has only one and some additional non-conserved subunits). CHRAC plays roles in the regulation of RNA polymerase II transcription and in DNA replication and repair. |
| Terminal bouton | Terminal inflated portion of the axon, containing the specialized apparatus necessary to release neurotransmitters. The axon terminus is considered to be the whole region of thickening and the terminal bouton is a specialized region of it. |
| Viral RNA-directed RNA polymerase complex | |
| Pwp2p-containing subcomplex of 90S preribosome | A protein complex that forms a subcomplex of the 90S preribosome and can interact directly with the 5' External Transcribed Spacer (ETS) of the full length pre-rRNA transcript. In S. cerevisiae, it sediments at 25-30 S and is composed of Pwp2p, Dip2p, Utp21p, Utp13p, Utp18p, and Utp6p. |
| Phosphopyruvate hydratase complex | A multimeric enzyme complex, usually a dimer or an octamer, that catalyzes the conversion of 2-phospho-D-glycerate to phosphoenolpyruvate and water. |
| MICOS complex | |
| Mitotic cohesin complex | A cohesin complex that mediates sister chromatid cohesion during mitosis; has a subunit composition distinct from that of the meiotic cohesin complex. |
| Cortical actin cytoskeleton | The portion of the actin cytoskeleton, comprising filamentous actin and associated proteins, that lies just beneath the plasma membrane. |
| glycosylphosphatidylinositol-mannosyltransferase I complex | |
| SMN-Gemin2 complex | A protein complex that contains the survival motor neuron (SMN) protein and Gemin2; may form the stable core of the larger SMN complex. |
| interleukin-28 receptor complex | A protein complex that binds interleukin-28 and interleukin-29. Composed of two subunits, IL-28R alpha and IL-10R beta. |
| Secretory granule | A small subcellular vesicle, surrounded by a membrane, that is formed from the Golgi apparatus and contains a highly concentrated protein destined for secretion. Secretory granules move towards the periphery of the cell and upon stimulation, their membranes fuse with the cell membrane, and their protein load is exteriorized. Processing of the contained protein may take place in secretory granules. |
| Mitochondrial intermembrane space | The region between the inner and outer lipid bilayers of the mitochondrial envelope. |
| MIB complex | |
| Fibrillar center | A structure found most metazoan nucleoli, but not usually found in lower eukaryotes; surrounded by the dense fibrillar component; the zone of transcription from multiple copies of the pre-rRNA genes is in the border region between these two structures. |
| ISWI-type complex | Any nuclear protein complex that contains an ATPase subunit of the imitation switch (ISWI) family. ISWI ATPases are involved in assembling chromatin and in sliding and spacing nucleosomes to regulate transcription of nuclear RNA polymerases I, II, and III and also DNA replication, recombination and repair. |
| SUMO activating enzyme complex | A conserved heterodimeric complex with SUMO activating enzyme activity. |
| Cell cortex | The region of a cell that lies just beneath the plasma membrane and often, but not always, contains a network of actin filaments and associated proteins. |
| Germ plasm | Differentiated cytoplasm associated with a pole of an oocyte, egg or early embryo that will be inherited by the cells that will give rise to the germ line. |
| ADA complex | |
| Pole plasm | Differentiated cytoplasm associated with a pole (animal, vegetal, anterior, or posterior) of an oocyte, egg or early embryo. |
| MLL3/4 complex | A protein complex that can methylate lysine-4 of histone H3, and which contains either of the protein subunits MLL3 or MLL4 in mammals, or equivalent in other species. |
| Large latent transforming growth factor-beta complex | A protein complex containing latency-associated proteins (LAPs), mature disulphide-linked dimeric TGF-beta, and latent TGF-beta binding proteins (LTBPs). TGF-beta is mostly secreted as part of the large latent complex, and must be subsequently released from the LLC in order to bind to cell surface receptors. |
| Prespliceosome | A spliceosomal complex that is formed by association of the 5' splice site and the branch point sequence with specific snRNPs. The prespliceosome includes many proteins in addition to those found in the bound snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation. Prespliceosome complexes are not active for splicing, but are instead an early step in the assembly of a spliceosomal complex. |
| Auxin efflux carrier complex | |
| Cleavage furrow | In animal cells, the first sign of cleavage, or cytokinesis, is the appearance of a shallow groove in the cell surface near the old metaphase plate. A contractile ring containing actin and myosin is located just inside the plasma membrane at the location of the furrow. Ring contraction is associated with centripetal growth of the membrane that deepens the cleavage furrow and divides the cytoplasm of the two daughter cells. While the term 'cleavage furrow' was initially associated with animal cells, such a structure occurs in many other types of cells, including unicellular protists. |
| Cholinergic synapse | |
| Cytoplasmic dynein complex | Any dynein complex that catalyzes movement along a cytoplasmic microtubule; cytoplasmic dynein complexes participates in many transport activities in eukaryotes, such as mRNA localization, intermediate filament transport, nuclear envelope breakdown, apoptosis, transport of centrosomal proteins, mitotic spindle assembly, virus transport, kinetochore functions, and movement of signaling and spindle checkpoint proteins. Subunits associated with the dynein heavy chain mediate association between dynein heavy chain and cargoes,and may include light chains and light intermediate chains. |
| Ku70:Ku80 complex | Heterodimeric protein complex composed of a 70 kDa and a 80 kDa subunit, binds DNA through a channel formed by the heterodimer. Functions in DNA double stranded break repair, chromosome maintenance, transcription regulation, V(D)J recombination, and activation of DNA-PK. |
| Late endosome membrane | The lipid bilayer surrounding a late endosome. |
| methionine-importing ABC transporter complex | |
| NSL complex | A histone acetyltransferase complex that catalyzes the acetylation of a histone H4 lysine residues at several positions. In human, it contains the catalytic subunit MOF, NSL1/KIAA1267, NSL2/KANSL2, NSL3/KANSL3, MCRS1, PHF20, OGT1, WDR5 and HCF1. |
| methionine-importing complex | |
| Intrinsic component of mitochondrial inner membrane | The component of the mitochondrial inner membrane consisting of the gene products that have some covalently attached part (e.g. peptide sequence or GPI anchor) which spans or is embedded in one or both leaflets of the membrane. |
| Intrinsic component of mitochondrial membrane | The component of the mitochondrial membrane consisting of the gene products that have some covalently attached part (e.g. peptide sequence or GPI anchor) which spans or is embedded in one or both leaflets of the membrane. |
| Protein storage vacuole | A storage vacuole that contains a lytic vacuole; identified in plants. |
| M band | The midline of aligned thick filaments in a sarcomere; location of specific proteins that link thick filaments. Depending on muscle type the M band consists of different numbers of M lines. |
| MutLbeta complex | A heterodimer involved in the recognition of base-base and small insertion/deletion mismatches. In human the complex consists of two subunits, MLH1 and PMS1. |
| Ciliary neurotrophic factor receptor complex | A protein complex that acts as a receptor for the cytokine ciliary neurotrophic factor (CNTF). In humans the receptor complex is a hexamer composed of two molecules each of CNTF and CNTFR and one molecule each of gp130 and LIFR. |
| CIA complex | The cytosolic iron-sulfur protein assembly (CIA) complex mediates the incorporation of iron-sulfur clusters into apoproteins involved in DNA metabolism and genomic integrity. |
| Centriolar satellite | A small (70-100 nm) cytoplasmic granule that contains a number of centrosomal proteins; centriolar satellites traffic toward microtubule minus ends and are enriched near the centrosome. |
| Derlin-1 retrotranslocation complex | |
| Golgi stack | The set of thin, flattened membrane-bounded compartments, called cisternae, that form the central portion of the Golgi complex. The stack usually comprises cis, medial, and trans cisternae; the cis- and trans-Golgi networks are not considered part of the stack. |
| SREBP-SCAP complex | A protein complex formed by the association of sterol regulatory element binding protein (SREBP) and SREBP-cleavage-activating protein (SCAP) in the ER membrane; in the absence of sterols, the SREBP-SCAP complex is packaged into COPII vesicles and travels to the Golgi apparatus to be processed. |
| Golgi membrane | The lipid bilayer surrounding any of the compartments of the Golgi apparatus. |
| Astral microtubule | Any of the spindle microtubules that radiate in all directions from the spindle poles and are thought to contribute to the forces that separate the poles and position them in relation to the rest of the cell. |
| VCB complex | A protein complex that possesses ubiquitin ligase activity; the complex is usually pentameric; for example, in mammals the subunits are pVHL, elongin B, elongin C, cullin-2 (Cul2), and Rbx1. |
| UDP-N-acetylglucosamine transferase complex | A multienzyme, heterooligomeric complex involved in dolichyl-linked oligosaccharide synthesis. In yeast the complex is composed of Alg7p, which catalyzes the first step (GlcNAc1-PP-Dol from dolichol-phosphate and UDP-GlcNAc), and Alg13p plus Alg14p, the catalytic and anchoring subunits respectively, which together catalyze the second step (GlcNAc2-PP-dolichol from GlcNAc1-PP-Dol and UDP-GlcNAc) of dolichyl-linked oligosaccharide synthesis. |
| Glycinergic synapse | |
| Phagophore assembly site | |
| i-AAA complex | Protease complex of the mitochondrial inner membrane whose catalytic residues lie on the intermembrane space side of the inner membrane; involved in mitochondrial protein turnover. Contains a subunit belonging to the AAA family of ATP-dependent metalloproteases. |
| Calcium channel complex | An ion channel complex through which calcium ions pass. |
| Cul2-RING ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul2 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by an elongin-BC adaptor and a SOCS/BC box protein. |
| Rough endoplasmic reticulum membrane | The lipid bilayer surrounding the rough endoplasmic reticulum. |
| Mitochondrial processing peptidase complex | A protein complex that consists of a catalytic alpha subunit (alpha-MPP) and a regulatory beta subunit (beta-MPP), and catalyzes the release of N-terminal targeting peptides from precursor proteins imported into the mitochondrion. |
| light-harvesting complex, peripheral complex | Bacteriochlorophyll a binding complex that is peripherally associated to the bacterial reaction center. |
| calcium- and calmodulin-dependent protein kinase complex | An enzyme complex which in eukaryotes is composed of four different chains: alpha, beta, gamma, and delta. The different isoforms assemble into homo- or heteromultimeric holoenzymes composed of 8 to 12 subunits. Catalyzes the phosphorylation of proteins to O-phosphoproteins. |
| Ubiquinone biosynthesis complex | |
| Sperm annulus | The ring-like, filamentous structure located at the distal end of the midpiece of the sperm flagellum; the annulus is thought to form a diffusion barrier between the midpiece and the principal piece and serve as a stabilizing structure for tail rigidity. |
| NoRC complex | An ISWI complex that contains an ATPase subunit of the ISWI family (specifically SNF2H in mammals, which contain two ISWI homologs) and a Tip5 homolog. In mammals, NoRC is involved in regulation of transcription from RNAP I and RNA polymerase III promoters. |
| Replication fork protection complex | A protein complex conserved in eukaryotes and associated with the replication fork; the complex stabilizes stalled replication forks and is thought to be involved in coordinating leading- and lagging-strand synthesis and in replication checkpoint signaling. |
| Slit-Robo signaling complex | A protein-carbohydrate complex that consists of a transmembrane roundabout (Robo) receptor, an extracellular Slit ligand and heparin/heparan sulfate. |
| Chromatoid body | A ribonucleoprotein complex found in the cytoplasm of male germ cells, composed of exceedingly thin filaments that are consolidated into a compact mass or into dense strands of varying thickness that branch to form an irregular network. Contains mRNAs, miRNAs, and protein components involved in miRNA processing (such as Argonaute proteins and the endonuclease Dicer) and in RNA decay (such as the decapping enzyme DCP1a and GW182). |
| Aster | An array of microtubules emanating from a spindle pole MTOC that do not connect to kinetochores. |
| Transforming growth factor beta activated kinase 1 complex | A protein complex that possesses protein kinase activity and activates the I-kappa B kinase complex (IKK) and mitogen-activated protein (MAP) kinases in response to TRAF6 signaling. It comprises the catalytic subunit TAK1 complexed to the regulatory subunits, termed TABs (TAK1-binding subunits). |
| interleukin-13 receptor complex | A protein complex that binds interleukin-13; consists of two chains, interleukin-13 receptor alpha1 chain and interleukin-4 receptor alpha chain. |
| Lipopolysaccharide receptor complex | A multiprotein complex that consists of at least three proteins, CD14, TLR4, and MD-2, each of which is glycosylated and which functions as a lipopolysaccharide (LPS) receptor that primes the innate immune response against bacterial pathogens. |
| piP-body | A P granule that contains the PIWIL4-TDRD9 module, a set of proteins that act in the secondary piRNA pathway. |
| Endolysosome | An transient hybrid organelle formed by fusion of a late endosome with a lysosome, and in which active degradation takes place. |
| ER membrane insertion complex | A protein complex that is involved in the post-translational delivery of tail-anchored (TA) membrane proteins to the endoplasmic reticulum. TA membrane proteins, also called type II transmembrane proteins, contain a single C-terminal transmembrane region. Some ER membrane insertion complex subunits are conserved between different species such as mammals and budding yeast. |
| Activin B complex | |
| Endodeoxyribonuclease complex | |
| Integrin alpha6-beta4 complex | An integrin complex that comprises one alpha6 subunit and one beta1 subunit. |
| methylcrotonoyl-CoA carboxylase complex | |
| Side of membrane | A cellular component consisting of one leaflet of a membrane bilayer and any proteins embedded or anchored in it or attached to its surface. |
| U6 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U6. |
| Junctional membrane complex | Complex formed in muscle cells between the membrane of the sarcoplasmic reticulum and invaginations of the plasma membrane (T-tubules). |
| Azurophil granule | Primary lysosomal granule found in neutrophil granulocytes. Contains a wide range of hydrolytic enzymes and is released into the extracellular fluid. |
| RNA-directed RNA polymerase complex | A protein complex that possesses RNA-directed RNA polymerase activity. |
| Primary cell wall | A plant cell wall that is still able to expand, permitting cell growth. Primary cell walls contain more pectin than secondary walls and no lignin is present. |
| tetraspanin-enriched microdomain | A pre-organized unit composed either of adhesion molecules (mainly integrins and members of the Ig superfamily), signaling receptors and/or enzyme-enriched plasma membrane domains that compartmentalizes cellular processes. Tetraspanin-enriched microdomains might be specially suited for the regulation of avidity of adhesion receptors and the compartmentalization of enzymatic activities. |
| aminoacyl-tRNA synthetase multienzyme complex | A multienzyme complex found in all multicellular eukaryotes composed of eight proteins with aminoacyl-tRNA synthetase activities (abbreviated as: ArgRS, AspRS, GluProRS, GlnRS, IleRS, LeuRS, LysRS, MetRS where RS is the enzyme, preceded by the amino acid it uses as a substrate) as well as three non-synthetase proteins (p43, p38, and p18) with diverse functions. Several of these subunits are known dimers, so the total polypeptide count in the multisynthetase complex is at least fifteen. All of the enzymes in this assembly catalyze the same reaction, the covalent attachment of an amino acid to either the 2'- or 3'-hydroxyl of the 3'-terminal adenosine of tRNA, but using different substrates. |
| Growth hormone receptor complex | A receptor complex that consists of two identical subunits and binds growth hormone. |
| Glycolate oxidase complex | |
| Immunological synapse | An area of close contact between a lymphocyte (T-, B-, or natural killer cell) and a target cell formed through the clustering of particular signaling and adhesion molecules and their associated membrane rafts on both the lymphocyte and the target cell and facilitating activation of the lymphocyte, transfer of membrane from the target cell to the lymphocyte, and in some situations killing of the target cell through release of secretory granules and/or death-pathway ligand-receptor interaction. |
| Microneme | A small, elongated secretory organelle that forms part of the apical complex, located along the main axis of an apicomplexan parasite cell within the extreme apical region and at the periphery under the inner membrane complex. Of the specialized secretory compartments identified in apicomplexans, micronemes discharge their contents first, during initial contact of the parasite's apical pole with the host cell surface. Micronemal proteins function during parasite attachment and penetration into the target cell. |
| Cytoplasmic ubiquitin ligase complex | A ubiquitin ligase complex found in the cytoplasm. |
| Endocytic vesicle | A membrane-bounded intracellular vesicle formed by invagination of the plasma membrane around an extracellular substance. Endocytic vesicles fuse with early endosomes to deliver the cargo for further sorting. |
| Stereocilia coupling link | A structure involved in coupling stereocilia to one another in sensory hair cells There are four morphologically distinct types: tip links, horizontal top connectors, shaft connectors and ankle links. Tip links and horizontal top connectors are the only inter-stereocilia links associated with mature cochlea, whereas ankle links appear during development of the auditory hair bundle. |
| Organelle envelope lumen | The region between the inner and outer lipid bilayers of an organelle envelope. |
| MCM8-MCM9 complex | A hexameric protein complex composed of MCM8 and MCM9 and involved in homologous recombination repair following DNA interstrand cross-links. |
| Mitochondrial alpha-ketoglutarate dehydrogenase complex | Mitochondrial complex that possesses alpha-ketoglutarate dehydrogenase activity. |
| beta-N-acetylhexosaminidase complex | |
| Stereocilia tip link | A stereocilia link that is formed by a fine filament running more or less vertically upward from the tip of each shorter stereocilium to attach at a higher point on its adjacent taller neighbor. Tilting the bundle puts tension on the filaments, which pull on mechanically gated ion channels in the membrane of the stereocilia. |
| Negative cofactor 2 complex | A heterodimeric protein complex that can stably associate with TATA-binding protein on promoters, thereby preventing the assembly of transcription factors TFIIA and TFIIB and leading to repression of RNA polymerase II transcription. The two subunits, NC2alpha (Drap1) and NC2beta (Dr1), dimerize through histone fold domains of the H2A/H2B type present in the amino termini. |
| Mitochondrial ribosome | A ribosome found in the mitochondrion of a eukaryotic cell; contains a characteristic set of proteins distinct from those of cytosolic ribosomes. |
| Zymogen granule membrane | The lipid bilayer surrounding a zymogen granule. |
| Transcription factor TFIIH core complex | |
| Signal peptidase complex | A protein complex that is located in the endoplasmic reticulum membrane and cleaves the signal sequence from precursor proteins following their transport out of the cytoplasmic space. |
| Extrahaustorial matrix | The space between the symbiont plasma membrane and the extrahaustorial membrane of the host. |
| Amylin receptor complex 3 | |
| Nuclear aryl hydrocarbon receptor complex | An aryl hydrocarbon receptor (AhR) complex found in the nucleus; ; consists of ligand-bound AhR and the aryl hydrocarbon receptor nuclear translocator (ARNT). |
| 1-alkyl-2-acetylglycerophosphocholine esterase complex | |
| Rix1 complex | A protein complex that comprises Rix1p, Ipi1p and Ipi3p, and is required for processing of ITS2 sequences from 35S pre-rRNA. The Rix1 complex has been identified in budding yeast and fission yeast, and members of this complex are conserved in higher eukaryotes. |
| Organellar ribosome | A ribosome contained within a subcellular membrane-bounded organelle. |
| Integrin alphav-beta6 complex | An integrin complex that comprises one alphav subunit and one beta6 subunit. |
| Cytoskeleton of presynaptic active zone | |
| Presynaptic active zone cytoplasmic component | |
| Sperm flagellum | A microtubule-based flagellum (or cilium) that is part of a sperm, a mature male germ cell that develops from a spermatid. |
| Podosome | An actin-rich adhesion structure characterized by formation upon cell substrate contact and localization at the substrate-attached part of the cell, contain an F-actin-rich core surrounded by a ring structure containing proteins such as vinculin and talin, and have a diameter of 0.5 mm. |
| Presynaptic cytoskeleton | |
| Lateral wall of outer hair cell | |
| CENP-T-W-S-X complex | |
| Mast cell granule | Coarse, bluish-black staining cytoplasmic granules, bounded by a plasma membrane and found in mast cells and basophils. Contents include histamine, heparin, chondroitin sulfates, chymase and tryptase. |
| Mitochondrial crista junction | A tubular structure of relatively uniform size that connects a mitochondrial crista to the mitochondrial inner boundary membrane. |
| Prefoldin complex | A multisubunit chaperone that is capable of delivering unfolded proteins to cytosolic chaperonin, which it acts as a cofactor for. In humans, the complex is a heterohexamer of two PFD-alpha and four PFD-beta type subunits. In Saccharomyces cerevisiae, it also acts in the nucleus to regulate the rate of elongation by RNA polymerase II via a direct effect on histone dynamics. |
| Axolemma | The portion of the plasma membrane surrounding an axon; it is a specialized trilaminar random mosaic of protein molecules floating within a fluid matrix of highly mobile phospholipid molecules, 7-8 nm in thickness. |
| RSF complex | An ISWI complex that contains an ATPase subunit of the ISWI family (SNF2H in mammals) and an RSF1 homolog. It mediates nucleosome deposition and generates regularly spaced nucleosome arrays. In mammals, RSF is involved in regulation of transcription from RNA polymerase II promoters). |
| Golgi-associated vesicle | Any vesicle associated with the Golgi complex and involved in mediating transport within the Golgi or between the Golgi and other parts of the cell. |
| Divisome complex | |
| Pilus | A proteinaceous hair-like appendage on the surface of bacteria ranging from 2-8 nm in diameter. |
| Cytosolic aryl hydrocarbon receptor complex | An aryl hydrocarbon receptor complex found in the cytosol, in which the ligand-binding subunit AhR is not bound to ligand; consists of AhR, two molecules of HSP90, the protein kinase c-Src, and the immunophilin XAP2/AIP. |
| Prp19 complex | A protein complex consisting of Prp19 and associated proteins that is involved in the transition from the precatalytic spliceosome to the activated form that catalyzes step 1 of splicing, and which remains associated with the spliceosome through the second catalytic step. It is widely conserved, found in both yeast and mammals, though the exact composition varies. In S. cerevisiae, it contains Prp19p, Ntc20p, Snt309p, Isy1p, Syf2p, Cwc2p, Prp46p, Clf1p, Cef1p, and Syf1p. |
| Mitochondrial fatty acid beta-oxidation multienzyme complex | A complex that includes the long-chain 3-hydroxyacyl-CoA dehydrogenase and long-chain enoyl-CoA hydratase activities in two subunits (alpha and beta), catalyzing two steps of the fatty acid beta-oxidation cycle within the mitochondrial matrix. |
| Parallel fiber | A parallel fiber results from the bifurcation of a cerebellar granule cell axon in the molecular layer into two diametrically opposed branches, that are oriented parallel to the long axis of the folium. |
| vacuole-mitochondrion membrane contact site | |
| Primary lysosome | A lysosome before it has fused with a vesicle or vacuole. |
| Presynaptic active zone | A specialized region of the plasma membrane and cell cortex of a presynaptic neuron; encompasses a region of the plasma membrane where synaptic vesicles dock and fuse, synaptic vesicles, and a specialized cortical cytoskeletal matrix. |
| carbamoyl-phosphate synthase complex | A protein complex that catalyzes the formation of carbamoyl phosphate; comprises a small subunit that binds and cleaves glutamine, and a large subunit that accepts the ammonia group cleaved from glutamine, binds all of the remaining substrates and effectors, and carries out all of the other catalytic events. |
| RENT complex | A protein complex that mediates transcriptional silencing at the rDNA locus (the name derives from regulator of nucleolar silencing and telophase). In Saccharomyces the complex contains Net1p, Sir2p, Cdc14p, and at least one more subunit. |
| Uniplex complex | A calcium channel complex in the mitochondrial inner membrane capable of highly-selective calcium channel activity. Its components include the EF-hand-containing proteins mitochondrial calcium uptake 1 (MICU1) and MICU2, the pore-forming subunit mitochondrial calcium uniporter (MCU) and its paralog MCUb, and the MCU regulator EMRE. |
| GBAF complex | |
| Fatty acid beta-oxidation multienzyme complex | A multienzyme complex possessing three kinds of enzymes that catalyze the chain reactions in the fatty acid beta-oxidation cycle, enoyl-CoA hydratase (ECH), 3-hydroxyacyl-CoA dehydrogenase (HACD), and acetyl-CoA C-acyltransferase (KACT). |
| Mitochondrial large ribosomal subunit | The larger of the two subunits of a mitochondrial ribosome. Two sites on the ribosomal large subunit are involved in translation: the aminoacyl site (A site) and peptidyl site (P site). |
| actin-based cell projection | |
| Upper tip-link density | |
| Yb body | A cytoplasmic part that appears as an electron-dense sphere of around 1.5 micron diameter containing Yb protein found in somatic cells of ovary and testis. There are one to two Yb bodies per cell. |
| Cell cortex region | |
| Cell projection membrane | The portion of the plasma membrane surrounding a cell surface projection. |
| Mitotic spindle assembly checkpoint MAD1-MAD2 complex | |
| Organellar large ribosomal subunit | The larger of the two subunits of an organellar ribosome. Two sites on the ribosomal large subunit are involved in translation: the aminoacyl site (A site) and peptidyl site (P site). |
| DNA replication factor A complex | A conserved heterotrimeric complex that binds nonspecifically to single-stranded DNA and is required for multiple processes in eukaryotic DNA metabolism, including DNA replication, DNA repair, and recombination. In all eukaryotic organisms examined the complex is composed of subunits of approximately 70, 30, and 14 kDa. |
| Dendritic knob | |
| Formate dehydrogenase complex | An enzyme complex that catalyzes the dehydrogenation of formate to produce carbon dioxide (CO2). |
| Z chromosome | The sex chromosome present in both sexes of species in which the female is the heterogametic sex. Two copies of the Z chromosome are present in each somatic cell of males and one copy is present in females. |
| Golgi-associated vesicle membrane | The lipid bilayer surrounding a vesicle associated with the Golgi apparatus. |
| interleukin-3 receptor complex | A protein complex that binds interleukin-3; comprises an alpha and a beta subunit. The alpha chain is specific to the interleukin-3 receptor, whereas the beta chain is shared with the receptors for granulocyte-macrophage colony-stimulating factor and interleukin-5. |
| RISC-loading complex | A trimeric ribonucleoprotein complex that and is required for the formation of a mature RNA induced silencing complex (RISC). In humans the complex is composed of the endonuclease Dicer (DICER1) and TRBP (TARBP2) in association with the Argonaute protein Ago2 (EIF2C2/AGO2). Within the complex, Dicer and TRBP are required to process precursor miRNAs (pre-miRNAs) to mature miRNAs and then load them onto Ago2. Ago2 bound to the mature miRNA constitutes the minimal RISC and may subsequently dissociate from Dicer and TRBP. |
| WICH complex | An ISWI complex that contains an ATPase subunit of the ISWI family (specifically SNF2H in mammals, which contain two ISWI homologs) and WSTF (Williams Syndrome Transcription Factor). WICH plays roles in regulation of RNAP I and III transcription and in DNA replication and repair. |
| Rpd3L complex | A histone deacetylase complex which deacetylates histones across gene coding regions. Composed of a catalytic histone deacetylase subunit, an Sds-3 family protein, a SIN3 family co-repressor, a WD repeat protein, and a zf- PHD finger (Clr6, Sds3, Pst1, Prw1, Png2 in Schizosaccharomyces pombe; Rpd3p, Sin3p, Ume1p, Pho23p, Sap30p, Sds3p, Cti6p, Rxt2p, Rxt3p, Dep1p, Ume6p and Ash1p in Saccharomyces cerevisiae). |
| Transcription factor TFIIIB complex | A transcription factor complex that is involved in regulating transcription from RNA polymerase III (Pol III) promoters. TFIIIB contains the TATA-binding protein (TBP) and two Pol III-specific proteins, B'' and BRF. |
| Dinoflagellate cingulum | A cell surface furrow that wraps around a dinoflagellate cell; the transverse flagellum lies in it. |
| interleukin-10 receptor complex | |
| Neuron projection membrane | The portion of the plasma membrane surrounding a neuron projection. |
| Distal dendrite | |
| Pick body | Cellular inclusion composed of numerous tau fibrils arranged in a disorderly array. Tau protein is a major component, though Pick bodies also contain ubiquitin, alpha-synuclein, and apolipoprotein E. |
| Nrd1 complex | A complex that functions in transcription termination of RNA polymerase II transcribed non-coding RNAs. This complex interacts with the carboxy-terminal domain (CTD) of PolII and the terminator sequences in the nascent RNA transcript. In yeast this complex consists of Nrd1p, Nab3p, and Sen1p. |
| Fatty acid elongase complex | |
| Phosphatidylinositol 3-kinase complex, class IA | A class I phosphatidylinositol 3-kinase complex that possesses 1-phosphatidylinositol-4-phosphate 3-kinase activity; comprises a catalytic class IA phosphoinositide 3-kinase (PI3K) subunit and an associated SH2 domain-containing regulatory subunit that is a member of a family of related proteins often called p85 proteins. Through the interaction with the SH2-containing adaptor subunits, Class IA PI3K catalytic subunits are linked to tyrosine kinase signaling pathways. |
| B875 antenna complex | Protein complex that surrounds and transfers excitation energy directly to the bacterial reaction center; binds bacteriochlorophyll a and has a single absorption band between 870 and 890 nm. |
| light-harvesting complex, core complex | Light harvesting complex associated with the reaction complex of photosynthetic purple bacteria. |
| Xanthine dehydrogenase complex | |
| Phagocytic vesicle | A membrane-bounded intracellular vesicle that arises from the ingestion of particulate material by phagocytosis. |
| Lysosomal multienzyme complex | A protein complex found in the lysosome that contains beta-galactosidase, cathepsin A, alpha-neuraminidase and N-acetylgalactosamine-6-sulfate sulfatase, and is involved in glycosaminoglycan catabolism. |
| U4 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U4. |
| Plasma membrane light-harvesting complex | A plasma membrane protein-pigment complex that may be closely or peripherally associated to photosynthetic reaction centers that participate in harvesting and transferring radiant energy to the reaction center. Examples of this complex are found in bacterial species. |
| Perinuclear theca | A condensed cytoplasmic structure that covers the nucleus of mammalian spermatozoa except for a narrow zone around the insertion of the tail. It shows two distinct regions, a subacrosomal layer and, continuing caudally beyond the acrosomic system, the postacrosomal sheath. The perinuclear theca has been considered a cytoskeletal scaffold responsible for maintaining the overall architecture of the mature sperm head; however, recent studies indicate that the bulk of its constituent proteins are not traditional cytoskeletal proteins but rather a variety of cytosolic proteins. |
| Sexine | |
| Granular component | A structure found in the nucleolus, which contains nearly completed preribosomal particles destined for the cytoplasm. |
| Mitochondrial intermembrane space protein transporter complex | Soluble complex of the mitochondrial intermembrane space composed of various combinations of small Tim proteins; acts as a protein transporter to guide proteins to the Tim22 complex for insertion into the mitochondrial inner membrane. |
| Glial cell projection | A prolongation or process extending from a glial cell. |
| Dsl1/NZR complex | |
| MLL1 complex | A protein complex that can methylate lysine-4 of histone H3. MLL1/MLL is the catalytic methyltransferase subunit, and the complex also contains the core components ASH2L, HCFC1/HCF1 WDR5 and RBBP5. |
| Female germ cell nucleus | The nucleus of the female germ cell, a reproductive cell in females. |
| Germinal vesicle | The enlarged, fluid filled nucleus of a primary oocyte, the development of which is suspended in prophase I of the first meiotic division between embryohood and sexual maturity. |
| Protease inhibitor complex | A heterodimeric protein complex that contains a protease inhibitor and a protease; formation of the complex inhibits protease activity. |
| Cell surface furrow | A furrow that may be found on the cell surface. Examples are the cleavage furrow observed during cytokinesis in animal cells, and the cingulum and sulcus found in some dinoflagellates. |
| Host extracellular space | |
| Mitochondrial small ribosomal subunit | The smaller of the two subunits of a mitochondrial ribosome. |
| Ciliary vesicle | |
| Serine protease inhibitor complex | A heterodimeric protein complex that contains a serine protease inhibitor and a protease; formation of the complex inhibits serine protease activity. |
| Integrin alpha3-beta1 complex | An integrin complex that comprises one alpha3 subunit and one beta1 subunit. |
| Rad17 RFC-like complex | A pentameric protein complex related to replication factor C, which loads a trimeric complex of checkpoint proteins (known as the checkpoint clamp or 9-1-1 complex) onto DNA at damage sites; functions in DNA damage cell cycle checkpoints. In Schizosaccharomyces pombe the subunits are known as Rad17, Rfc2, Rfc3, Rfc4, and Rfc5, while in Saccharomyces cerevisiae the subunits are known as Rad24p, Rfc2p, Rfc3p, Rfc4p, and Rfc5p. |
| Organellar small ribosomal subunit | The smaller of the two subunits of an organellar ribosome. |
| Mon1-Ccz1 complex | A protein complex that functions as a guanine nucleotide exchange factor (GEF) and converts Rab-GDP to Rab-GTP. In S. cerevisiae, this complex consists of at least Mon1 and Ccz1, and serves as a GEF for the Rab Ypt7p. |
| Microvillus | Thin cylindrical membrane-covered projections on the surface of an animal cell containing a core bundle of actin filaments. Present in especially large numbers on the absorptive surface of intestinal cells. |
| Chromaffin granule | Specialized secretory vesicle found in the cells of adrenal glands and various other organs, which is concerned with the synthesis, storage, metabolism, and secretion of epinephrine and norepinephrine. |
| acetyl-CoA decarbonylase/synthase-carbon monoxide dehydrogenase complex | A multifunctional enzyme complex composed of five different polypeptides that catalyzes the decarbonylation of acetyl-CoA, cleaves the C-C and C-S bonds in the acetyl moiety of acetyl-CoA, oxidizes the carbonyl group to CO2 and transfers the methyl group to tetrahydrosarcinapterin. These reactions are important for methanogenesis. |
| Retrotransposon nucleocapsid | A complex of the retrotransposon RNA genome, reverse transcriptase, integrase, and associated molecules required for reproduction and integration of the retrotransposon into the host genome; the main structural molecule of the nucleocapsid is often a gag protein homolog. |
| XY body | A structure found in a male mammalian spermatocyte containing an unpaired X chromosome that has become densely heterochromatic, silenced and localized at the nuclear periphery. |
| G protein-coupled receptor dimeric complex | |
| Apical dendrite | A dendrite that emerges near the apical pole of a neuron. In bipolar neurons, apical dendrites are located on the opposite side of the soma from the axon. |
| Grb2-Sos complex | A protein complex that contains Grb2 and the guanine nucleotide exchange factor Sos (or an ortholog thereof, such as mSos1), and is involved in linking EGFR activation to the p21-Ras pathway. |
| Schwann cell microvillus | Small finger-like extension of a Schwann cell that contacts the nodal membrane. |
| Messenger ribonucleoprotein complex | A ribonucleoprotein complex containing both protein and messenger RNA (mRNA) molecules. |
| Lamin filament | Any of a group of intermediate-filament proteins that form the fibrous matrix on the inner surface of the nuclear envelope. They are classified as lamins A, B and C. |
| Peptidase inhibitor complex | |
| Inward rectifier potassium channel complex | A protein complex which is capable of inward rectifier potassium channel activity. |
| Hydroxyisourate hydrolase complex | |
| retromer, cargo-selective complex | |
| haptoglobin-hemoglobin complex | A protein complex formed by the stable binding of a haptoglobin to hemoglobin. |
| interleukin-23 receptor complex | A protein complex that binds interleukin-23. The complex comprises two subunits, including the same beta subunit found in the interleukin-12 receptor. |
| Keratin filament | A filament composed of acidic and basic keratins (types I and II), typically expressed in epithelial cells. The keratins are the most diverse classes of IF proteins, with a large number of keratin isoforms being expressed. Each type of epithelium always expresses a characteristic combination of type I and type II keratins. |
| Fc-gamma receptor III complex | |
| DPS complex | |
| Ruffle | Projection at the leading edge of a crawling cell; the protrusions are supported by a microfilament meshwork. |
| Meprin A complex | A protein complex that is located in the cell membrane, and is involved in the metabolism of peptides, including neuropeptides. The complex has metalloendopeptidase activity that catalyzes the hydrolysis of protein and peptide substrates, preferentially on carboxyl side of hydrophobic residues. |
| Dehydrodolichyl diphosphate synthase complex | |
| Sperm glycocalyx | |
| CERF complex | An ISWI complex that contains an ATPase subunit of the ISWI family (specifically SNF2L in mammals, which contain two ISWI homologs) and a CECR2 homolog. In mammals, CERF is involved in regulation of transcription from RNA polymerase II promoters. |
| Acrosomal membrane | The membrane that surrounds the acrosomal lumen. The acrosome is a special type of lysosome in the head of a spermatozoon that contains acid hydrolases and is concerned with the breakdown of the outer membrane of the ovum during fertilization. |
| Activating signal cointegrator 1 complex | |
| Integrin alpha9-beta1 complex | An integrin complex that comprises one alpha9 subunit and one beta1 subunit. |
| Leading edge membrane | The portion of the plasma membrane surrounding the leading edge of a motile cell. |
| Septin collar | A tubular, hourglass-shaped structure composed of highly ordered arrays of septin filaments; in budding yeast cells, the septin collar forms from the initial septin ring by expanding into the daughter cell. |
| Amylin receptor complex 2 | |
| Glutamate dehydrogenase complex | |
| Plasma membrane-derived chromatophore | A pigment-bearing structure that is derived from the cytoplasmic membrane, sometimes consisting of simple invaginations and sometimes a complete vesicle. This component is found in certain photosynthetic bacteria and cyanobacteria. |
| Apical plasma membrane urothelial plaque | |
| Nuclear pore linkers | A substructure of the nuclear pore complex (NPC) that serves to connect members of the central transport channel (composed of FG-nucleoporins) to the core scaffold (composed of the inner and outer NPC rings). In S. cerevisiae, the linkers are Nic96p and Nup82p. In vertebrates, they are Nup93 and Nup88. Components are arranged in 8-fold symmetrical 'spokes' around the central transport channel. Both linkers can be isolated in association with specific FG-nucleoporins, complexes that are sometimes referred to as the Nic96 complex (Nic96p-Nsp1p-Nup49p-Nup57p) and the Nup82 complex (Nup82p-Nup116p-Nup159p-Gle2p). |
| Germ cell nucleus | The nucleus of a germ cell, a reproductive cell in multicellular organisms. |
| DUBm complex | A protein complex that forms part of SAGA-type complexes SAGA and SLIK, and mediates deubiquitination of histone H2B. In S. cerevisiae, the DUBm consists of the proteins Ubp8p, Sgf11p, Sus1p, and Sgf73p. |
| Phagophore assembly site membrane | |
| Kinocilium | A nonmotile primary cilium that is found at the apical surface of auditory receptor cells. The kinocilium is surrounded by actin-based stereocilia. |
| 9+2 non-motile cilium | |
| Stereocilia tip-link density | |
| Metaphase plate | The intracellular plane, located halfway between the poles of the spindle, where chromosomes align during metaphase of mitotic or meiotic nuclear division. |
| Integrin alpha11-beta1 complex | An integrin complex that comprises one alpha11 subunit and one beta1 subunit. |
| npBAF complex | A SWI/SNF-type complex that is found in neural stem or progenitor cells, and in human contains actin and proteins encoded by the ARID1A/BAF250A or ARID1B/BAF250B, SMARCD1/BAF60A, SMARCD3/BAF60C, SMARCA2/BRM/BAF190B, SMARCA4/BRG1/BAF190A, SMARCB1/BAF47, SMARCC1/BAF155, SMARCE1/BAF57, SMARCC2/BAF170, PHF10/BAF45A, ACTL6A/BAF53A genes. The npBAF complex is essential for the self-renewal/proliferative capacity of the multipotent neural stem cells. |
| tRNA methyltransferase complex | A multimeric protein complex involved in the methylation of specific nucleotides in tRNA. |
| MOZ/MORF histone acetyltransferase complex | A histone acetyltransferase complex that has histone H3 acetyltransferase and coactivator activities. Subunits of the human complex include MYST3/MOZ, MYST4/MORF, ING5, EAF6 and one of BRPF1, BRD1/BRPF2 and BRPF3. |
| Integrin alphav-beta8 complex | An integrin complex that comprises one alphav subunit and one beta8 subunit. |
| DiaA complex | |
| 3-methyl-2-oxobutanoate dehydrogenase (lipoamide) complex | A protein complex that catalyzes the reaction 3-methyl-2-oxobutanoate + lipoamide = S-(2-methylpropanoyl)-dihydrolipoamide + carbon dioxide (CO2). This requires thiamine diphosphate; the enzyme also acts on (S)-3-methyl-2-oxopentanoate and 4-methyl-2-oxo-pentanoate. |
| Storage vacuole | A vacuole that functions primarily in the storage of materials, including nutrients, pigments, waste products, and small molecules. |
| interleukin-18 receptor complex | A protein complex that binds interleukin-18; comprises an alpha and a beta subunit. |
| PAR polarity complex | |
| Phycobilisome | Any of the granules, approximately 32 nm x 48 nm and consisting of highly aggregated phycobiliproteins, that are attached in arrays to the external face of a thylakoid membrane in algae of the phyla Cyanophyta and Rhodophyta, where they function as light-harvesting devices in photosynthesis. Excitation energy in the phycobilisome flows in the sequence: phycoerythrin, phycocyanin, allophycocyanin before passing to the antenna chlorophyll of photosystem II. |
| Cdc42 GTPase complex | A protein complex formed by the association of the small GTPase Cdc42 with additional proteins. In Schizosaccharomyces the complex contains the Cdc42, Ras1, Scd1, Scd2, andShk1 proteins, and functions in the Ras1-Scd GTPase signalling pathway. |
| Atg12-Atg5-Atg16 complex | A protein complex required for the expansion of the autophagosomal membrane. In budding yeast, this complex consists of Atg12p, Atg5p and Atg16p. |
| Cysteine synthase complex | Cysteine synthase is a multienzyme complex made up, in E. coli, of the heteromeric hexamer serine acetyltransferase and the homodimer O-acetylserine (thiol)-lyase A. |
| U4/U6 snRNP | A ribonucleoprotein complex that contains base-paired U4 and U6 small nuclear RNAs. |
| 9+0 non-motile cilium | |
| succinate-CoA ligase complex | A heterodimeric enzyme complex, usually composed of an alpha and beta chain. Functions in the TCA cycle, hydrolyzing succinyl-CoA into succinate and CoA, thereby forming ATP or GTP. |
| Golgi transport complex | A complex of proteins that, in vitro, stimulates intra-Golgi transport; a 13S complex, about 800 kDa in size and consists of at least five polypeptides. In yeast, this complex is called the Sec34/35 complex and is composed of eight subunits (Sec34p, Sec35p, Dor1p, Cod1p, Cod2p, Cod3p, Cod4p, and Cod5p). |
| Myosin XVI complex | |
| ACF complex | An ISWI complex that contains an ATPase subunit of the ISWI family (SNF2H in mammals, Isw2 in S. cerevisiae), an ACF1 homolog, and generally no other subunits, though Xenopus is an exception with a third non-conserved subunit. ACF plays roles in regulation of RNA polymerase II transcription and in DNA replication and repair. |
| Vesicle coat | A membrane coat found on a coated vesicle. |
| Core mediator complex | A protein complex that interacts with the carboxy-terminal domain of the largest subunit of RNA polymerase II and plays an active role in transducing the signal from a transcription factor to the transcriptional machinery. The core mediator complex has a stimulatory effect on basal transcription, and contains most of the same subdomains as the larger form of mediator complex -- a head domain comprising proteins known in Saccharomyces as Srb2, -4, and -5, Med6, -8, and -11, and Rox3 proteins; a middle domain comprising Med1, -4, and -7, Nut1 and -2, Cse2, Rgr1, Soh1, and Srb7 proteins; and a tail consisting of Gal11p, Med2p, Pgd1p, and Sin4p -- but lacks the regulatory subcomplex comprising Ssn2, -3, and -8, and Srb8 proteins. Metazoan core mediator complexes have similar modular structures and include homologs of yeast Srb and Med proteins. |
| Pericentric heterochromatin | Heterochromatin that is located adjacent to the CENP-A rich centromere 'central core' and characterized by the modified histone H3K9me3. |
| Nonhomologous end joining complex | A protein complex that plays a role in DNA double-strand break repair via nonhomologous end joining. Such complexes typically contain a specialized DNA ligase (e.g. Lig4 in eukaryotes) and one or more proteins that bind to DNA ends. |
| Granulocyte macrophage colony-stimulating factor receptor complex | The heterodimeric receptor for granulocyte macrophage colony-stimulating factor. |
| Nitrogenase complex | An enzyme complex composed of two proteins, dinitrogenase and nitrogenase reductase; dinitrogenase is tetrameric with an alpha2-beta2 structure and nitrogenase reductase is a homodimer, and both are associated with metal ions, which differ between species. Both proteins are required for the enzyme activity of the complex, the formation of oxidized ferredoxin and ammonia from reduced ferredoxin and nitrogen. |
| Ciliary tip | Part of the cilium where the axoneme ends. The ciliary tip has been implicated in ciliary assembly and disassembly, as well as signal transduction. |
| Integrator complex | A protein complex that stably associates with the C-terminus of RNA polymerase II and mediates 3'-end processing of small nuclear RNAs generated by RNA polymerase II. |
| pyrroline-5-carboxylate reductase complex | |
| Inner mucus layer | The inner of two mucus layers secreted by epithelial cells in the colon; the inner mucus layer is firmly attached to the epithelium, is densely packed with a compact stratified appearance and is devoid of bacteria. |
| Box H/ACA RNP complex | A ribonucleoprotein complex that contains an RNA of the box H/ACA type, a subtype of the small nucleolar RNA (snoRNA) family. RNA pseudouridylation (isomerization of uridine to pseudouridine) is the major, and most likely the ancestral, function of H/ACA RNPs, although some have evolved other functions. Pseudouridylation targets include both large and small ribosomal RNAs (rRNAs), and on U2 small nuclear RNA (U2 snRNA). |
| Integrin alphaE-beta7 complex | An integrin complex that comprises one alphaE subunit and one beta7 subunit. |
| clathrin-coated pit | |
| DASH complex | A large protein complex, containing around 8-10 subunits in yeast, including Duo1p, Dam1p, Dad1p and Ask1p. The complex forms part of the kinetochore, associates with microtubules when the kinetochore attaches to the spindle, and plays a role in spindle attachment, chromosome segregation and spindle stability. |
| Cortical cytoskeleton | The portion of the cytoskeleton that lies just beneath the plasma membrane. |
| Ciliary base | Area of the cilium (also called flagellum) where the basal body and the axoneme are anchored to the plasma membrane. The ciliary base encompasses the distal part of the basal body, transition fibers and transition zone and is structurally and functionally very distinct from the rest of the cilium. In this area proteins are sorted and filtered before entering the cilium, and many ciliary proteins localize specifically to this area. |
| Coated vesicle membrane | The lipid bilayer surrounding a coated vesicle. |
| pre-primosome complex | |
| mitochondria-associated endoplasmic reticulum membrane | |
| ERCC4-ERCC1 complex | A heterodimeric nucleotide-excision repair complex that has endonuclease activity specific for bubble structures characteristic of certain DNA lesions. The subunits are known as XPF/ERCC4 and ERCC1 in mammals, and Rad1p and Rad10p in S. cerevisiae. |
| New mitotic spindle pole body | The spindle pole body that is formed by spindle pole body duplication, and to which proteins involved in mitotic exit signaling (for example, the septation initiation network in fission yeast) localize. |
| glycosylphosphatidylinositol-mannosyltransferase II complex | |
| Cul3-RING ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul3 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by a BTB-domain-containing protein. |
| Acrosomal matrix | A structural framework, or 'dense core' at the interior of an acrosome. May regulate the distribution of hydrolases within the acrosome and their release during the acrosome reaction. |
| Tapasin-ERp57 complex | |
| PCNA complex | A protein complex composed of three identical PCNA monomers, each comprising two similar domains, which are joined in a head-to-tail arrangement to form a homotrimer. Forms a ring-like structure in solution, with a central hole sufficiently large to accommodate the double helix of DNA. Originally characterized as a DNA sliding clamp for replicative DNA polymerases and as an essential component of the replisome, and has also been shown to be involved in other processes including Okazaki fragment processing, DNA repair, translesion DNA synthesis, DNA methylation, chromatin remodeling and cell cycle regulation. |
| Rough endoplasmic reticulum | The rough (or granular) endoplasmic reticulum (ER) has ribosomes adhering to the outer surface; the ribosomes are the site of translation of the mRNA for those proteins which are either to be retained within the cisternae (ER-resident proteins), the proteins of the lysosomes, or the proteins destined for export from the cell. Glycoproteins undergo their initial glycosylation within the cisternae. |
| Presynaptic membrane | A specialized area of membrane of the axon terminal that faces the plasma membrane of the neuron or muscle fiber with which the axon terminal establishes a synaptic junction; many synaptic junctions exhibit structural presynaptic characteristics, such as conical, electron-dense internal protrusions, that distinguish it from the remainder of the axon plasma membrane. |
| Yae1-Lto1 complex | |
| acetyl-CoA carboxylase complex | A protein complex that catalyzes the first step in long-chain fatty acid biosynthesis. For example, in E. coli the complex is heterohexameric and composed of biotin carbonyl carrier protein, biotin carboxylase and the acetate CoA-transferase complex. |
| Mitotic septin complex | A heterooligomeric septin complex that acts during mitotic cell division. |
| Urease complex | A multiprotein nickel-containing complex that possesses urease activity (catalysis of the hydrolysis of urea to ammonia and carbon dioxide). |
| Mitochondrial creatine kinase complex | An octomeric protein complex having creatine kinase activity. |
| post-anaphase microtubule array | |
| Plastid membrane | Either of the lipid bilayers that surround a plastid and form the plastid envelope. |
| Dxr protein complex | |
| PSI associated light-harvesting complex I | Protein-pigment complex associated with photosystem I. |
| Noc complex | Any of several heterodimers containing one or two Noc proteins, associated with preribosomal complexes; involved in ribosome biogenesis. |
| Metallochaperone complex | |
| Plastid envelope | The double lipid bilayer enclosing a plastid and separating its contents from the rest of the cytoplasm; includes the intermembrane space. |
| Glycine cleavage complex | A protein complex that catalyzes the reversible oxidation of glycine. In E. coli, it has four components: dihydrolipoamide dehydrogenase, glycine dehydrogenase (decarboxylating), lipoyl-GcvH-protein and aminomethyltransferase, also known as L, P, H, and T. |
| Rad6-Rad18 complex | |
| Ribonuclease MRP complex | A ribonucleoprotein complex that contains an RNA molecule of the snoRNA family, and cleaves the rRNA precursor as part of rRNA transcript processing. It also has other roles: In S. cerevisiae it is involved in cell cycle-regulated degradation of daughter cell-specific mRNAs, while in mammalian cells it also enters the mitochondria and processes RNAs to create RNA primers for DNA replication. |
| Creatine kinase complex | A protein complex having creatine kinase activity. |
| Exine | The outer layer of the pollen grain wall which is composed primarily of sporopollenin. |
| Rad51C-XRCC3 complex | A DNA recombinase mediator complex that contains the Rad51 paralogs RAD51C and XRCC3, or orthologs thereof. |
| RNA polymerase I upstream activating factor complex | |
| Tic complex | The translocon of the inner envelope of chloroplasts, which facilitates the import of proteins across the chloroplast inner membrane. |
| Chloroplast inner membrane | The inner, i.e. lumen-facing, lipid bilayer of the chloroplast envelope; also faces the chloroplast stroma. |
| Plastid inner membrane | The inner, i.e. lumen-facing, lipid bilayer of the plastid envelope; also faces the plastid stroma. |
| Collagen network | |
| platelet-derived growth factor complex | |
| DNA topoisomerase III-beta-TDRD3 complex | |
| Sec62/Sec63 complex | A protein complex involved in the posttranslational targeting of proteins to the ER. In yeast, it is a tetrameric complex consisting of Sec62p, Sec63p, Sec71p and Sec72p. |
| BCL-2 complex | A homodimeric protein complex consisting of BCL-2, a member of the Bcl-2 family of anti- and proapoptotic regulators. |
| H3 histone acetyltransferase complex | A multisubunit complex that catalyzes the acetylation of histone H3. |
| AP-1 adaptor complex | A heterotetrameric AP-type membrane coat adaptor complex that consists of beta1, gamma, mu1 and sigma1 subunits and links clathrin to the membrane surface of a vesicle; vesicles with AP-1-containing coats are normally found primarily in the trans-Golgi network. In at least humans, the AP-1 complex can be heterogeneric due to the existence of multiple subunit isoforms encoded by different genes (gamma1 and gamma2, mu1A and mu1B, and sigma1A, sigma1B and sigma1C). |
| Clathrin coat of trans-Golgi network vesicle | A clathrin coat found on a vesicle of the trans-Golgi network. |
| trans-Golgi network transport vesicle membrane | The lipid bilayer surrounding a vesicle transporting substances between the trans-Golgi network and other parts of the cell. |
| Endoplasmic reticulum Sec complex | An endoplasmic reticulum membrane-associated complex involved in the translocation of proteins that are targeted to the ER. In yeast, this complex consists of two subcomplexes, namely, the Sec61 complex and the Sec62/Sec63 complex. |
| tRNA-splicing ligase complex | A protein complex that catalyzes the ligation of cleaved pre-tRNAs by directly joining spliced tRNA halves to mature-sized tRNAs by incorporating the precursor-derived splice junction phosphate into the mature tRNA as a canonical 3',5'-phosphodiester. |
| Bunina body | Small granular inclusions (about 1-3 microns in diameter) found in the anterior horn cells, and appearing either singly or in a group. Sometimes they are arranged in small beaded chains. Bunina bodies express cystatin C and consist of electron-dense amorphous material that contains tubules or vesicular structures. The amorphous material frequently includes a cytoplasmic island containing neurofilaments and other micro-organelles. |
| eNoSc complex | |
| G protein-coupled GABA receptor complex | |
| Histone locus body | A nuclear body associated with the histone gene locus that is thought to contain all of the factors necessary for histone mRNA transcription and pre-mRNA processing. In Drosophila, U7 snRNP is located in the histone locus body rather than the distinct Cajal body. |
| toxin-antitoxin complex | |
| Rhp55-Rhp57 complex | A conserved heterodimeric DNA recombinase mediator complex that contains the RecA family proteins Rhp55p and Rph57 in Schizosaccharomyces, or orthologs thereof (e.g. Rad55p and Rad57p in Saccharomyces). |
| insulin-responsive compartment | A small membrane-bounded vesicle that releases its contents by exocytosis in response to insulin stimulation; the contents are enriched in GLUT4, IRAP and VAMP2. |
| Complex of collagen trimers | |
| Elongator holoenzyme complex | A heterohexameric protein complex that is involved in modification of wobble nucleosides in tRNA, and exerts direct effects on transcriptional elongation and exocytosis. The complex can associate physically with hyperphosphorylated RNA polymerase II; it contains two discrete heterotrimeric subcomplexes. |
| TCR signalosome | A multi-protein complex containing at least the T-cell receptor complex and the LAT (linker for activation of T cells) scaffold protein. Also contains a variety of signaling proteins including co-receptors, kinases, phosphatases and adaptors such as CD8. Connects events on the plasma membrane to distal signaling cascades to ultimately modulate T cell biology. |
| RPAP3/R2TP/prefoldin-like complex | |
| Myb complex | A multisubunit complex consisting of Myb and other proteins that regulates site specific DNA replication, gene amplification and transcriptional repression. |
| Apical recycling endosome | |
| IgM B cell receptor complex | An IgM immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| Mitotic spindle pole body | The microtubule organizing center on a spindle that forms as part of mitosis; functionally homologous to the animal cell centrosome. |
| Cytoplasmic microtubule | Any microtubule in the cytoplasm of a cell. |
| skein-like inclusion | Intracytoplasmic filamentous structure frequently encountered in preparations immunostained for ubiquitin. |
| Dom34-Hbs1 complex | |
| RNA polymerase transcription factor SL1 complex | A RNA polymerase I-specific transcription factor complex that contains the TATA-box-binding protein (TBP) and at least three TBP-associated factors including proteins known in mammals as TAFI110, TAFI63 and TAFI48. |
| trans-Golgi network transport vesicle | A vesicle that mediates transport between the trans-Golgi network and other parts of the cell. |
| Integrin alpha10-beta1 complex | An integrin complex that comprises one alpha10 subunit and one beta1 subunit. |
| Decaprenyl diphosphate synthase complex | A complex that possesses di-trans,poly-cis-decaprenylcistransferase activity; involved in ubiquinone biosynthesis. |
| Methionine adenosyltransferase complex | A multimeric enzyme complex composed of variable numbers of catalytic alpha subunits, and noncatalytic beta subunits. The beta subunits are believed to have a regulatory function. The enzyme complex catalyzes the synthesis of S-adenosylmethionine (AdoMet), which is the major methyl group donor, participating in the methylation of proteins, DNA, RNA, phospholipids, and other small molecules. |
| W chromosome | The sex chromosome present in females of species in which the female is the heterogametic sex; generally, the sex chromosome that pairs with the Z chromosome in the heterogametic sex. The W chromosome is absent from the cells of males and present in one copy in the somatic cells of females. |
| bub1-bub3 complex | Protein complex that associates with the kinetochores. |
| laminin-1 complex | A laminin complex composed of alpha1, beta1 and gamma1 polypeptide chains. |
| Mpp10 complex | A protein complex that forms a subcomplex of the 90S preribosome. In S. cerevisiae, it is composed of Mpp10p, Imp3p and Imp4p. |
| Fusiform vesicle | |
| Neuronal cell body | The portion of a neuron that includes the nucleus, but excludes cell projections such as axons and dendrites. |
| Extrachromosomal rDNA circle | Circular DNA molecules encoding ribosomal RNA that are replicated independently of chromosomal replication. These molecules originate in the chromosome but are excised and circularized, often by intramolecular homologous recombination between direct tandem repeats. |
| Pollen wall | The complex wall surrounding a pollen grain. |
| SPOTS complex | A multiprotein complex at least composed of serine palmitoyltransferases and ORM proteins (known as ORMDL proteins in mammals and other higher vertebrates) that plays a key role in sphingolipid homeostasis. |
| Apical cortex | The region that lies just beneath the plasma membrane on the apical edge of a cell. |
| NVT complex | |
| Sin3 complex | A multiprotein complex that functions broadly in eukaryotic organisms as a transcriptional repressor of protein-coding genes, through the gene-specific deacetylation of histones. Amongst its subunits, the Sin3 complex contains Sin3-like proteins, and a number of core proteins that are shared with the NuRD complex (including histone deacetylases and histone binding proteins). The Sin3 complex does not directly bind DNA itself, but is targeted to specific genes through protein-protein interactions with DNA-binding proteins. |
| GAIT complex | A protein complex which mediates interferon-gamma-induced transcript-selective translation inhibition in inflammation processes. The complex binds to stem loop-containing GAIT elements in the 3'-UTR of diverse inflammatory mRNAs and suppresses their translation by blocking the recruitment of the 43S ribosomal complex to m7G cap-bound eIF4G. In humans it includes RPL13A, EPRS, SYNCRIP and GAPDH; mouse complexes lack SYNCRIP. |
| bacterial-type flagellum filament | The long (approximately 20 nm), thin external structure of the flagellum, which acts as a propeller. Examples of this component are found in bacteria. |
| Dendritic shaft | Cylindric portion of the dendrite, directly stemming from the perikaryon, and carrying the dendritic spines. |
| Monopolin complex | A protein complex required for clamping microtubule binding sites, ensuring orientation of sister kinetochores to the same pole (mono-orientation) during meiosis I. In the yeast S. cerevisiae this complex consists of Csm1p, Lrs4p, Hrr25p and Mam1p; in S. pombe Psc1 and Mde4 have been identified as subunits. |
| VCP-NSFL1C complex | |
| PR-DUB complex | A multimeric protein complex that removes monoubiquitin from histone H2A. In Drosophila and mammals, the core of the complex is composed of Calypso/BAP1 and Asx/ASXL1, respectively. |
| Cytoplasmic region | |
| TRAPPI protein complex | |
| Chloroplast membrane | Either of the lipid bilayers that surround a chloroplast and form the chloroplast envelope. |
| Cortical Lewy body | Cytoplasmic inclusion similar to a classical Lewy body but lacking a halo of protein fibrils. |
| Sperm head | |
| Cyst wall | |
| Signal recognition particle receptor complex | A transmembrane heterodimeric protein located in the membrane of the rough endoplasmic reticulum. Both subunits contain GTPase domains with which signal recognition particle interacts. In the presence of GTP and SRP receptor, SRP is released from the ribosome-nascent chain complex. |
| UTP-C complex | A protein complex that forms a subcomplex of the 90S preribosome. In S. cerevisiae, it is composed of Rrp7p, Utp22p, Ckb1p, Cka1p, Ckb2p and Cka2p. |
| small-subunit processome | A large ribonucleoprotein complex that is an early preribosomal complex. In S. cerevisiae, it has a size of 80S and consists of the 35S pre-rRNA, early-associating ribosomal proteins most of which are part of the small ribosomal subunit, the U3 snoRNA and associated proteins. |
| Integrin alpha6-beta1 complex | An integrin complex that comprises one alpha6 subunit and one beta1 subunit. |
| Climbing fiber | The axon of inferior olive neuron that projects to the cerebellar cortex, largely via the inferior cerebellar peduncle. They range in diameter from 1-3 um and are myelinated until they enter the granule cell layer. They give off collaterals to the deep cerebellar nuclei. They synapse extensively with the dendrites of Purkinje cells in the molecular layer, where each fiber branches repeatedly to climb along the Purkinje cell dendritic tree. Each Purkinje cell is innervated by only a single climbing fiber. |
| Meiotic recombination initiation complex | A protein complex that initiates the formation of double-strand breaks (DSBs) required for meiotic recombination. Consists of a protein that catalyses formation of the double-strand breaks (Spo11 in S. cerevisiae and Rec12 in S. pombe), and a number of accessory proteins. |
| Chloroplast envelope | The double lipid bilayer enclosing the chloroplast and separating its contents from the rest of the cytoplasm; includes the intermembrane space. |
| Dcp1-Dcp2 complex | |
| ERMES complex | A protein complex that links the endoplasmic reticulum with mitochondria and may have a role in promoting exchange of calcium and phospholipids between the two organelles. The complex is also associated with actively replicating mitochondrial DNA nucleoids, and may further coordinate mitochondrial genome replication and membrane growth. |
| Actin rod | A cellular structure consisting of parallel, hexagonally arranged actin tubules, comprising filamentous actin and associated proteins. Found in the germinating spores of Dictyostelium discoideum. |
| Cuticular plate | A dense network of actin filaments found beneath the apical cell surface of hair cells, and into which stereocilia are inserted. |
| Cell septum | A structure composed of peptidoglycan and often chitin in addition to other materials. It usually forms perpendicular to the long axis of a cell or hypha and grows centripetally from the cell wall to the center of the cell and often functions in the compartmentalization of a cell into two daughter cells. |
| LYSP100-associated nuclear domain | A nuclear body that is enriched in the lymphoid cell-specific protein LYSp100B; LANDs are globular, electron-dense structures and are morphologically distinct from the annular structures characteristic of PML bodies. |
| Interchromatin granule | A class of nuclear body measuring 20-25 nm in diameter and distributed throughout the interchromatin space, linked together by thin fibrils. They are believed to be storage centers for various snRNAs, snRNPs, serine/arginine-rich proteins and RNA polymerase II. A typical mammalian cell contains 25-50 clusters of interchromatin granules. Interchromatin granule clusters do not contain the heterogeneous nuclear RNA-binding proteins (hnRNPs). |
| AP-2 adaptor complex | A heterotetrameric AP-type membrane coat adaptor complex that consists of alpha, beta2, mu2 and sigma2 subunits, and links clathrin to the membrane surface of a vesicle; vesicles with AP-2-containing coats are normally found primarily near the plasma membrane, on endocytic vesicles. In at least humans, the AP-2 complex can be heterogeneric due to the existence of multiple subunit isoforms encoded by different alpha genes (alphaA and alphaC). |
| Clathrin coat of endocytic vesicle | A clathrin coat found on an endocytic vesicle. |
| Thylakoid lumen | The volume enclosed by a thylakoid membrane. |
| Clathrin coat of coated pit | The coat found on coated pits and the coated vesicles derived from coated pits; comprises clathrin and the AP-2 adaptor complex. |
| Mitochondrial crista | Any of the inward folds of the mitochondrial inner membrane. Their number, extent, and shape differ in mitochondria from different tissues and organisms. They appear to be devices for increasing the surface area of the mitochondrial inner membrane, where the enzymes of electron transport and oxidative phosphorylation are found. Their shape can vary with the respiratory state of the mitochondria. |
| 3M complex | A protein complex, at least composed of CUL7, CCDC8 and OBSL1, that is required for maintaining microtubule and genome integrity. |
| Clathrin vesicle coat | A clathrin coat found on a vesicle. |
| U11 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U11. |
| Macrolide transmembrane transporter complex | |
| Multiple synapse bouton, contacting multiple dendrites | |
| Apical ectoplasmic specialization | |
| clathrin-coated endocytic vesicle membrane | The lipid bilayer surrounding a clathrin-coated endocytic vesicle. |
| Serine C-palmitoyltransferase complex | An enzyme complex that catalyzes the transfer of a palmitoyl on to serine, forming 3-dehydro-D-sphinganine. |
| Sperm head-tail coupling apparatus | |
| Starch utilization system complex | A bacterial cell envelope-associated multiprotein system, which binds and degrades starch. |
| Pairing center | A special chromosome region located towards one end of a chromosome that contains dispersed copies of short, repetitive DNA sequences and functions as a cis-acting element essential for presynaptic homologous chromosome pairing and chromosome-nuclear envelope attachment. |
| protein-cysteine S-palmitoyltransferase complex | |
| Endoplasmic reticulum palmitoyltransferase complex | A dimeric complex of the endoplasmic reticulum that catalyzes S-palmitoylation, the addition of palmitate (C16:0) or other long-chain fatty acids to proteins at a cysteine residue. |
| Protein kinase 5 complex | |
| Ooplasm | |
| clathrin-coated vesicle membrane | The lipid bilayer surrounding a clathrin-coated vesicle. |
| Autosome | Any chromosome other than a sex chromosome. |
| MCM core complex | A protein complex that contains Mcm4, Mcm6, and Mcm7 proteins, and possesses DNA helicase activity. In the heterohexameric MCM complex, the Mcm4/6/7 proteins form a stable core, and Mcm2, Mcm3, and Mcm5 are more peripherally associated. |
| Type Ib terminal bouton | |
| Recombination nodule | An electron dense structure that is associated with meiotic chromosomes. |
| B-WICH complex | |
| Ubiquitin conjugating enzyme complex | Any complex that possesses ubiquitin conjugating enzyme activity. |
| HSP90-CDC37 chaperone complex | |
| Integrin alphaM-beta2 complex | An integrin complex that comprises one alphaM subunit and one beta2 subunit. |
| Cellulose synthase complex | A large, multimeric protein complex, organized in a rosette, which catalyzes the biosynthesis of cellulose for the plant cell wall. |
| TIS granule | |
| New cell pole | |
| Axonemal central apparatus | |
| Catalytic step 1 spliceosome | A spliceosomal complex that is formed by the displacement of the two snRNPs from the precatalytic spliceosome; three snRNPs including U5 remain associated with the mRNA. This complex, sometimes called the activated spliceosome, is the catalytically active form of the spliceosome, and includes many proteins in addition to those found in the associated snRNPs. |
| Ciliary pocket collar | |
| Sorting endosome | A multivesicular body surrounded by and connected with multiple tubular compartments with associated vesicles. |
| Palmitoyltransferase complex | A protein complex with palmitoyltransferase activity. |
| Cytoskeletal calyx | A large cytoskeletal structure located at the posterior end of the perinuclear theca of a mammalian sperm head. The nucleus is tightly associated with the calyx, which contains calicin and basic cylicin proteins. |
| proton-transporting ATP synthase complex | A proton-transporting two-sector ATPase complex that catalyzes the phosphorylation of ADP to ATP during oxidative phosphorylation. The complex comprises a membrane sector (F0) that carries out proton transport and a cytoplasmic compartment sector (F1) that catalyzes ATP synthesis by a rotational mechanism; the extramembrane sector (containing 3 a and 3 b subunits) is connected via the d-subunit to the membrane sector by several smaller subunits. Within this complex, the g and e subunits and the 9-12 c subunits rotate by consecutive 120 degree angles and perform parts of ATP synthesis. This movement is driven by the hydrogen ion electrochemical potential gradient. |
| Photoreceptor disc membrane | Ovally-shaped membranous stack located inside the photoreceptor outer segment, and containing densely packed molecules of the photoreceptor protein rhodopsin that traverse the lipid bilayer. Disc membranes are apparently derived from the plasma membrane in the region of the cilium that connects the photoreceptor outer segment to the inner segment. |
| Platelet dense granule | Electron-dense granule occurring in blood platelets that stores and secretes adenosine nucleotides and serotonin. They contain a highly condensed core consisting of serotonin, histamine, calcium, magnesium, ATP, ADP, pyrophosphate and membrane lysosomal proteins. |
| Pollen tube | A tubular cell projection that is part of a pollen tube cell and extends from a pollen grain. |
| proton-transporting two-sector ATPase complex | A large protein complex that catalyzes the synthesis or hydrolysis of ATP by a rotational mechanism, coupled to the transport of protons across a membrane. The complex comprises a membrane sector (F0, V0, or A0) that carries out proton transport and a cytoplasmic compartment sector (F1, V1, or A1) that catalyzes ATP synthesis or hydrolysis. Two major types have been characterized: V-type ATPases couple ATP hydrolysis to the transport of protons across a concentration gradient, whereas F-type ATPases, also known as ATP synthases, normally run in the reverse direction to utilize energy from a proton concentration or electrochemical gradient to synthesize ATP. A third type, A-type ATPases have been found in archaea, and are closely related to eukaryotic V-type ATPases but are reversible. |
| Transcription factor TFIIK complex | |
| Nuclear matrix | The dense fibrillar network lying on the inner side of the nuclear membrane. |
| Axonal growth cone | The migrating motile tip of a growing nerve cell axon. |
| Transcription factor TFIIH holo complex | |
| Endoplasmic reticulum tubular network | An endoplasmic reticulum part that comprises the membranes with high curvature in cross-section. |
| Photoreceptor distal connecting cilium | |
| Cortical endoplasmic reticulum | A cortical network of highly dynamic tubules that are juxtaposed to the plasma membrane and undergo ring closure and tubule-branching movements. |
| Outer mucus layer | The outer of two mucus layers secreted by epithelial cells in the colon; the outer mucus layer is loosely packed and can be colonized by bacteria. |
| Cone cell pedicle | A specialized axon terminus which is produced by retinal cone cells. Pedicles are large, conical, flat end-feet (8-10 micrometers diameter) of the retinal cone axon that lie more or less side by side on the same plane at the outer edge of the outer plexiform layer (OPL). |
| Nodal receptor complex | A protein complex containing at least a type II activin receptor, a type I activin receptor, and a coreceptor (EGF-CFC protein) such as Cripto or Cryptic. Nodal receptor complexes are capable of binding a nodal protein and transducing the signal into the cell. |
| bacterial-type flagellum | A motor complex composed of an extracellular helical protein filament coupled to a rotary motor embedded in the cell envelope. |
| Spindle matrix | A proteinaceous, nuclear-derived structure that embeds the microtubule spindle apparatus from pole to pole in a microtubule-independent manner during mitosis. |
| Large ribosomal subunit | The larger of the two subunits of a ribosome. Two sites on the ribosomal large subunit are involved in translation, namely the aminoacyl site (A site) and peptidyl site (P site). |
| Tumor necrosis factor receptor superfamily complex | A receptor complex that contains one or more members of the tumor necrosis factor (TNF) receptor superfamily. |
| Myosin XII complex | |
| SCF-Skp2 ubiquitin ligase complex | |
| Rb-E2F complex | A multiprotein complex containing a heterodimeric E2F transcription factor and a Retinoblastoma (Rb) family member. This complex is capable of repressing transcription of E2F-regulated genes in order to regulate cell cycle progression. |
| Nicalin-NOMO complex | |
| Microtubule minus-end | The end of a microtubule that does not preferentially grow (polymerize). |
| Dendritic branch | A dendrite arising from another dendrite. |
| Lymphotoxin complex | |
| interleukin-20 receptor complex | |
| Fibronectin fibril | |
| Zymogen granule | A membrane-bounded, cytoplasmic secretory granule found in enzyme-secreting cells and visible by light microscopy. Contain zymogen, an inactive enzyme precursor, often of a digestive enzyme. |
| Granum | Distinct stack of lamellae seen within chloroplasts. Grana contain the pigments, electron transfer compounds, and enzymes essential to the light-dependent reactions of photosynthesis. |
| Septate junction | A cell-cell junction that forms a continuous band around each cell in an epithelium; within the septate junction the membranes of adjacent cells maintain a constant distance of approximately 15 nm; found in invertebrates. |
| esBAF complex | |
| DNA replication factor C complex | A complex of five polypeptides in eukaryotes, and two in prokaryotes, that loads the DNA polymerase processivity factor proliferating cell nuclear antigen (PCNA) onto DNA, thereby permitting processive DNA synthesis catalyzed by DNA polymerase. |
| Medial cortical node | A protein complex that contains the mid1, cdr2, wee1, klp8, and blt1 proteins, and is involved in contractile ring localization. Medial cortical node complexes appear as cortical dots in the middle of the cell during interphase, and function to recruit other ring components in early mitosis. |
| Endonuclease complex | |
| monolayer-surrounded lipid storage body | A subcellular organelle of plant cells surrounded by 'half-unit' or a monolayer membrane instead of the more usual bilayer. The storage body has a droplet of triglyceride surrounded by a monolayer of phospholipids, interacting with the triglycerides and the hydrophilic head groups facing the cytosol, and containing major protein components called oleosins. |
| Cytosolic large ribosomal subunit | The large subunit of a ribosome located in the cytosol. |
| Hyphal tip | The end, or tip, of a fungal hypha, where polarized growth occurs during hyphal elongation. |
| Periplasmic space | The region between the inner (cytoplasmic) and outer membrane (Gram-negative Bacteria) or cytoplasmic membrane and cell wall (Fungi and Gram-positive Bacteria). |
| Apoplast | The cell membranes and intracellular regions in a plant are connected through plasmodesmata, and plants may be described as having two major compartments: the living symplast and the non-living apoplast. The apoplast is external to the plasma membrane and includes cell walls, intercellular spaces and the lumen of dead structures such as xylem vessels. Water and solutes pass freely through it. |
| Myosin XV complex | |
| CKM complex | |
| Tubulin folding cofactor complex | |
| Transmembrane actin-associated (TAN) line | |
| TAP complex | A heterodimer composed of the subunits TAP1 and TAP2 (transporter associated with antigen presentation). Functions in the transport of antigenic peptides from the cytosol to the lumen of the endoplasmic reticulum. |
| CD40 receptor complex | A protein complex that contains at least CD40 (a cell surface receptor of the tumour necrosis factor receptor (TNFR) superfamily), and other signaling molecules. |
| clathrin-coated endocytic vesicle | A clathrin-coated, membrane-bounded intracellular vesicle formed by invagination of the plasma membrane around an extracellular substance. |
| Photoreceptor connecting cilium | A nonmotile primary cilium that has a 9+0 microtubule array and forms the portion of the axoneme traversing the boundary between the photoreceptor inner and outer segments. |
| Pilus tip | The pointed extremity furthest from the cell of a pilus. |
| Chiasma | A connection formed between chromatids, visible during meiosis, thought to be the point of the interchange involved in crossing-over. |
| Y-shaped link | |
| Eukaryotic translation elongation factor 1 complex | A multisubunit nucleotide exchange complex that binds GTP and aminoacyl-tRNAs, and catalyzes their codon-dependent placement at the A-site of the ribosome. In humans, the complex is composed of four subunits, alpha, beta, delta and gamma. |
| CSF1-CSF1R complex | |
| Mitochondrial respiratory chain complex III | A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. Contains about 10 polypeptide subunits including four redox centers: cytochrome b/b6, cytochrome c1 and an 2Fe-2S cluster. Catalyzes the oxidation of ubiquinol by oxidized cytochrome c1. |
| retromer, tubulation complex | |
| BORC complex | |
| senescence-associated heterochromatin focus | A transcriptionally-silent heterochromatin structure present in senescent cells. Contains the condensed chromatin of one chromosome and is enriched for histone modifications. Thought to repress expression of proliferation-promoting genes. |
| RAVE complex | A multisubunit complex that in Saccharomyces is composed of three subunits, Rav1p, Rav2p and Skp1p. Acts transiently to catalyze assembly of cytoplasmic V1, with membrane embedded V0 to form the V-ATPase holoenzyme. |
| Integrin alpha7-beta1 complex | An integrin complex that comprises one alpha7 subunit and one beta1 subunit. |
| Photoreceptor ribbon synapse | |
| Astrocyte projection | A prolongation or process extending from the soma of an astrocyte and wrapping around neurons. |
| Lateral part of cell | |
| Carboxysome | An organelle found in the Cyanobacteria consisting of a proteinaceous coat and enzymes for the fixation of carbon dioxide including mechanisms for the concentration of carbonate to increase the efficiency of fixation under low-carbon dioxide conditions. |
| Subpellicular microtubule | Singlet microtubules that lie underneath the inner membrane complex and emanate from the basal ring of the conoid. |
| Tertiary granule | A secretory granule that contains cathepsin and gelatinase and is readily exocytosed upon cell activation; found primarily in mature neutrophil cells. |
| Glycogen granule | Cytoplasmic bead-like structures of animal cells, visible by electron microscope. Each granule is a functional unit with the biosynthesis and catabolism of glycogen being catalyzed by enzymes bound to the granule surface. |
| Integrin alphaL-beta2 complex | An integrin complex that comprises one alphaL subunit and one beta2 subunit. |
| Diamine N-acetyltransferase complex | |
| Rab-protein geranylgeranyltransferase complex | A heterodimeric enzyme complex, which in mammals is composed of an alpha and a beta subunit, and which associates with an accessory protein Rep (Rab escort protein). Catalyzes of the transfer of a geranyl-geranyl group from geranylgeranyl pyrophosphate to a Rab protein. |
| Polyphosphate kinase complex | |
| Ruffle membrane | The portion of the plasma membrane surrounding a ruffle. |
| Cyclin D3-CDK4 complex | A protein complex consisting of cyclin D3 and cyclin-dependent kinase 4 (CDK4). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Transport vesicle membrane | The lipid bilayer surrounding a transport vesicle. |
| Ubiquitin activating enzyme complex | |
| EMC complex | |
| Histone pre-mRNA 3'end processing complex | A ribonucleoprotein that binds to specific sites in, and is required for cleavage of, the 3'-end of histone pre-mRNAs. The complex contains the U7 snRNP and additional proteins, including the stem-loop binding protein (SLBP) and the exonuclease 3'hExo/Eri-1. |
| Nuclear envelope lumen | The region between the two lipid bilayers of the nuclear envelope; 20-40 nm wide. |
| HAUS complex | A protein complex that localizes to interphase centrosomes and to mitotic spindle tubules and regulates mitotic spindle assembly and centrosome integrity; in human, the complex consists of eight subunits, some of which are homologous to subunits of the Drosophila Augmin complex. |
| Lysosomal lumen | The volume enclosed within the lysosomal membrane. |
| Semaphorin receptor complex | A stable binary complex of a neurophilin and a plexin, together forming a functional semaphorin receptor. |
| Myosin III complex | |
| Glutathione synthase complex | |
| vacuole-isolation membrane contact site | |
| Basal ectoplasmic specialization | |
| Clathrin adaptor complex | A membrane coat adaptor complex that links clathrin to a membrane. |
| MHC protein complex | A transmembrane protein complex composed of an MHC alpha chain and, in most cases, either an MHC class II beta chain or an invariant beta2-microglobin chain, and with or without a bound peptide, lipid, or polysaccharide antigen. |
| RPB4-RPB7 complex | |
| Retroviral intasome | |
| Acidocalcisome | An electron-dense acidic membrane-bounded organelle which contains a matrix of pyrophosphate and polyphosphates with bound calcium and other cations. |
| NLS-dependent protein nuclear import complex | A protein complex which usually consists of three components, e.g. in Xenopus, the importin alpha and beta-subunits and any protein which has a nuclear localization sequence (NLS). The complex acts to import proteins with an NLS into the nucleus through a nuclear pore. |
| Box H/ACA snoRNP complex | A box H/ACA RNP complex that is located in the nucleolus. |
| Integrin alphaD-beta2 complex | An integrin complex that comprises one alphaD subunit and one beta2 subunit. |
| Isw1b complex | |
| Costamere | Regular periodic sub membranous arrays of vinculin in skeletal and cardiac muscle cells, these arrays link Z-discs to the sarcolemma and are associated with links to extracellular matrix. |
| Dendrite terminus | A structure at the distal end of a dendrite adapted to carry out a specific function, e.g. dendriole. |
| TEAD-YAP complex | |
| AP-type membrane coat adaptor complex | Any of several heterotetrameric complexes that link clathrin (or another coat-forming molecule, as hypothesized for AP-3 and AP-4) to a membrane surface; they are found on coated pits and coated vesicles, and mediate sorting of cargo proteins into vesicles. Each AP complex contains two large (a beta and one of either an alpha, gamma, delta, or epsilon) subunits (110-130 kDa), a medium (mu) subunit (approximately 50 kDa), and a small (sigma) subunit (15-20 kDa). |
| CSL-Notch-Mastermind transcription factor complex | |
| GLI-SUFU complex | |
| [Ni-Fe] hydrogenase complex | A microbial enzyme complex which contains nickel and iron in its active site. In Acetomicrobium flavidum it is an alpha 2 beta 2 tetramer. |
| Secretory granule membrane | The lipid bilayer surrounding a secretory granule. |
| Endocytic patch | The part of the cell cortex consisting of an aggregation of proteins that will give rise to an endocytic vesicle. |
| Photoreceptor inner segment | The inner segment of a vertebrate photoreceptor containing mitochondria, ribosomes and membranes where opsin molecules are assembled and passed to be part of the outer segment discs. |
| Pronucleus | The nucleus of either the ovum or the spermatozoon following fertilization. Thus, in the fertilized ovum, there are two pronuclei, one originating from the ovum, the other from the spermatozoon that brought about fertilization; they approach each other, but do not fuse until just before the first cleavage, when each pronucleus loses its membrane to release its contents. |
| Pyroptosome complex | |
| cofilin-actin rod | |
| DNA recombinase complex | |
| Chlorosome | A large enclosure of aggregated pigment, typically bacteriochlorophyll c (BChl c), that acts as a light-harvesting antenna structure and is characteristic of green photosynthetic bacteria (e.g. Chlorobiaceae). The BChl aggregates are organized into lamellar elements by pigment-pigment rather than pigment-protein interactions. Chlorosomes also contain BChl a, carotenoids, quinones, lipids, and proteins, and are attached to the cytoplasmic membrane via a BChl a-containing protein baseplate. |
| IKKalpha-IKKalpha complex | A homodimeric protein complex containing two IkappaB kinase (IKK) alpha subunits. |
| Outer acrosomal membrane | The acrosomal membrane region that underlies the plasma membrane of the sperm. This membrane fuses with the sperm plasma membrane as part of the acrosome reaction. |
| Chromatin silencing complex | Any protein complex that mediates changes in chromatin structure that result in transcriptional silencing. |
| Cul7-RING ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul7 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by a Skp1 linker and an F-box protein. |
| Ubisch body | A small, granular structure that is found in the extracellular matrix of cell of the secretory tapetal layer that surrounds developing pollen grains. Ubisch bodies have a sporopollenin coat, are attached to the peritapetal wall, and may play a role in pollen development. |
| VCP-NPL4-UFD1 AAA ATPase complex | |
| Manchette | A conical shaped array of microtubules that completely covers the nucleus of a spermatid, thought to be involved in sperm head elongation. |
| Isw1a complex | |
| IPAF inflammasome complex | A protein complex that consists of three components, IPAF, NAIP and caspase-1, and includes among its functions the sensing of flagellin derived from Legionella pneumophila, Salmonella typhimurium, Pseudomonas aeruginosa and Shigella flexneri. |
| MMXD complex | A protein complex that contains the proteins MMS19, MIP18 and XPD, localizes to mitotic spindle during mitosis, and is required for proper chromosome segregation. |
| Collagen beaded filament | |
| Calyx of Held | The terminal specialization of a calyciferous axon which forms large synapses in the mammalian auditory central nervous system. |
| Prospore contractile ring | A contractile ring, i.e. a cytoskeletal structure composed of actin filaments and myosin, that forms beneath the plasma membrane of the prospore envelope in meiotic cells in preparation for completing cytokinesis. |
| Etioplast | A plastid arrested in the development of chloroplasts from proplastids due to absence of light or low light conditions. |
| Ribose phosphate diphosphokinase complex | A protein complex having ribose phosphate diphosphokinase activity. |
| Endocytic vesicle membrane | The lipid bilayer surrounding an endocytic vesicle. |
| Methyl coenzyme M reductase complex | |
| Phagolysosome | A membrane-bounded intracellular vesicle formed by maturation of an early phagosome following the ingestion of particulate material by phagocytosis; during maturation, phagosomes acquire markers of late endosomes and lysosomes. |
| Rixosome complex | |
| Intranuclear rod | |
| Muscle tendon junction | A cell-substrate junction found at the terminal anchorage site of skeletal muscle cells to tendons. |
| ATAC complex | |
| Vacuolar lumen | The volume enclosed within the vacuolar membrane. |
| RITS complex | A protein complex required for heterochromatin assembly; contains an Argonaute homolog, a chromodomain protein, and at least one additional protein; named for RNA-induced initiation of transcriptional gene silencing. |
| Bacterial microcompartment | |
| Ammonium transmembrane transporter complex | |
| Fusome | A large intracellular spectrin-rich structure that has been found in insect germline cells and mammalian hematopoietic cells. The fusome is an elongated, branched structure, formed from the spherical spectrosome organelle. |
| Ciliary pocket | Invagination of the plasma membrane from which a cilium (also called flagellum) protrudes. |
| Enhanceosome | A protein-DNA complex formed by the association of a distinct set of general and specific transcription factors with a region of enhancer DNA. The cooperative assembly of an enhanceosome confers specificity of transcriptional regulation. |
| Cdr2 medial cortical node complex | |
| COMA complex | A multiprotein complex in yeast consisting of Ctf19p, Okp1p, Mcm21p, and Ame1p. This complex bridges the subunits that are in contact with centromeric DNA and the subunits bound to microtubules during kinetochore assembly. |
| Nuclear origin of replication recognition complex | A multisubunit complex that is located at the replication origins of a chromosome in the nucleus. |
| HULC complex | A ubiquitin-conjugating enzyme complex that contains two RING finger proteins, which have ubiquitin ligase activity, in addition to a protein with ubiquitin-conjugating enzyme activity; catalyzes the ubiquitination of histone H2B at lysine 119 (or the equivalent residue). In Schizosaccharomyces the subunits are Rhp1, Brl2/Rfp1 and Brl1/Rfp2. |
| Ciliary inversin compartment | Proximal part of the ciliary shaft to which the inversin protein (also called Inv) specifically localizes. The inversin compartment appears to have a different protein composition than the rest of the cilium, although there is no structure that separates it form the distal part of the cilium. |
| Plastid outer membrane | The outer, i.e. cytoplasm-facing, lipid bilayer of the plastid envelope. |
| FHF complex | A protein complex that is composed of AKTIP/FTS, FAM160A2/p107FHIP, and one or more members of the Hook family of proteins, HOOK1, HOOK2, and HOOK3. The complex is thought to promote vesicle trafficking and/or fusion, and associates with the homotypic vesicular sorting complex (the HOPS complex). |
| laminin-6 complex | A laminin complex composed of alpha3, beta1 and gamma1 polypeptide chains. |
| Axon collateral | Any of the smaller branches of an axon that emanate from the main axon cylinder. |
| Xanthophore | A chromatophore containing yellow pigment. |
| Axonemal central pair | |
| Mitotic spindle pole | Either of the ends of a mitotic spindle, a spindle that forms as part of mitosis, where spindle microtubules are organized; usually contains a microtubule organizing center and accessory molecules, spindle microtubules and astral microtubules. |
| CLOCK-BMAL transcription complex | |
| Precatalytic spliceosome | A spliceosomal complex that is formed by the recruitment of a preassembled U5-containing tri-snRNP to the prespliceosome. Although all 5 snRNPs are present, the precatalytic spliceosome is catalytically inactive. The precatalytic spliceosome includes many proteins in addition to those found in the associated snRNPs. |
| Chloroplast outer membrane | The outer, i.e. cytoplasm-facing, lipid bilayer of the chloroplast envelope. |
| Rod photoreceptor outer segment | |
| Ethanolamine ammonia-lyase complex | |
| Apical cytoplasm | |
| INA complex | |
| Endoplasmic reticulum quality control compartment | A subcompartment of the endoplasmic reticulum in which proteins with improper or incorrect folding accumulate. Enzymes in this compartment direct proteins with major folding problems to translocation to the cytosol and degradation, and proteins with minor folding problems to the ER, to interact with chaperon proteins. |
| ESCRT IV complex | |
| Actin cortical patch | An endocytic patch that consists of an actin-containing structure found at the plasma membrane in cells; formed of networks of branched actin filaments that lie just beneath the plasma membrane and assemble, move, and disassemble rapidly. An example of this is the actin cortical patch found in Saccharomyces cerevisiae. |
| Endothelial microparticle | A blood microparticle that is derived from, and contains membrane receptors as well as other proteins characteristic of, an endothelial cell. |
| Swi5-Swi2 complex | A protein complex involved that contains proteins known in Schizosaccharomyces as Swi5 monomers and Swi2, and is involved in mating type switching. |
| FNIP-folliculin RagC/D GAP | |
| Kinetoplast | A sub-structure within the large single mitochondrion of kinetoplastid parasites and which is closely associated with the flagellar pocket and basal body of the flagellum. |
| Vitelline envelope | A glycoprotein-based structure that lies outside the plasma membrane and surrounds the egg before fertilization. |
| Integrin alphav-beta5 complex | An integrin complex that comprises one alphav subunit and one beta5 subunit. |
| Inner acrosomal membrane | The acrosomal membrane region that underlies the acrosomal vesicle and is located toward the sperm nucleus. This region is responsible for molecular interactions allowing the sperm to penetrate the zona pellucida and fuses with the egg plasma membrane. |
| Rad51B-Rad51C complex | A DNA recombinase mediator complex that contains the Rad51 paralogs RAD51B and RAD51C, or orthologs thereof. |
| plastid-encoded plastid RNA polymerase complex B | A plastid-encoded DNA-directed RNA polymerase complex that resembles eubacterial multisubunit RNA polymerases with a core composed of alpha, beta, and beta-prime subunits. An additional subunit, a sigma factor, is required for promoter recognition. PEP-B is distinguished from PEP-A by its sensitivity to the antibiotic rifampicin. PEP-B is found in both etioplasts and chloroplasts, but is the predominate form in etioplasts. It forms the core of the PEP-A form; the conversion from PEP-B to PEP-A occurs during chloroplast maturation. |
| Nephrocyte diaphragm | A specialized cell-cell junction found between nephrocytes of the insect kidney, which is adapted for filtration of hemolymph. The insect nephrocyte is anatomically and functionally similarity to the glomerular podocyte of vertebrates. |
| Telopode | |
| RCAF complex | A protein complex that facilitates the assembly of nucleosomes on to newly synthesized DNA. In Drosophila, the complex comprises ASF1 and histones H3 and H4. |
| Phosphoribosylaminoimidazole carboxylase complex | |
| PAM complex, Tim23 associated import motor | |
| Flemming body | A cell part that is the central region of the midbody characterized by a gap in alpha-tubulin staining. It is a dense structure of antiparallel microtubules from the central spindle in the middle of the intercellular bridge. |
| Golgi cisterna | Any of the thin, flattened membrane-bounded compartments that form the central portion of the Golgi complex. |
| Microspike | A dynamic, actin-rich projection extending from the surface of a migrating animal cell. |
| UBC13-UEV1A complex | A heterodimeric ubiquitin conjugating enzyme complex that catalyzes assembly of K63-linked polyubiquitin chains and is involved in NF-kappaB activation. In humans at least, the complex comprises the ubiquitin-conjugating enzyme UBC13 and ubiquitin-conjugating enzyme variant 1A (UEV1A). |
| Cellulose microfibril | A microfibril composed of cellulose arranged in orthogonal layers. Cellulose is a straight chain polysaccharide composed of B(14) linked glucose subunits. It is a major component of plant cell walls. Higher plant microfibrils are about 10nm in diameter and extremely long in relation to their width. The cellulose molecules are oriented parallel to the long axis of the microfibril in a paracrystalline array, which provides great tensile strength. The microfibrils are held in place by the wall matrix and their orientation is closely controlled by the cell. |
| Cleavage apparatus septin structure | |
| Gin4 complex | |
| Cellular bud neck septin ring | |
| Cellular bud neck septin structure | |
| Intercellular bridge | A direct connection between the cytoplasm of two cells that is formed following the completion of cleavage furrow ingression during cell division. They are usually present only briefly prior to completion of cytokinesis. However, in some cases, such as the bridges between germ cells during their development, they become stabilised. |
| Transcription factor TFIID complex | A complex composed of TATA binding protein (TBP) and TBP associated factors (TAFs); the total mass is typically about 800 kDa. Most of the TAFs are conserved across species. In TATA-containing promoters for RNA polymerase II (Pol II), TFIID is believed to recognize at least two distinct elements, the TATA element and a downstream promoter element. TFIID is also involved in recognition of TATA-less Pol II promoters. Binding of TFIID to DNA is necessary but not sufficient for transcription initiation from most RNA polymerase II promoters. |
| RES complex | A protein complex that is required for efficient splicing, and prevents leakage of unspliced pre-mRNAs from the nucleus (named for pre-mRNA REtention and Splicing). In Saccharomyces, the complex consists of Ist3p, Bud13p, and Pml1p. |
| Photosystem II reaction center | An integral membrane complex containing P680, the chlorophyll a molecule that functions as a primary electron donor. In the light, functioning as a water-plastoquinone oxidoreductase, it transfers electrons from water to plastoquinone. |
| Survivin complex | |
| ATG2-ATG18 complex | |
| Nucleosome disassembly/reassembly complex | |
| Lsm1-7-Pat1 complex | |
| RNA polymerase III complex | |
| Inositol phosphoceramide synthase complex | |
| Polytene chromosome | A type of chromosome in a polyploid cell, formed when multiple copies of homologous chromosomes are aligned side by side to give a giant chromosome in which distinct chromosome bands are readily visible. |
| pre-snoRNP complex | A ribonucleoprotein complex that contains a precursor small nucleolar RNA (pre-snoRNA) and associated proteins, and forms during small nucleolar ribonucleoprotein complex (snoRNP) assembly. Pre-snoRNP complexes may contain proteins not found in the corresponding mature snoRNP complexes. |
| Synapsis initiation complex | |
| Bam protein complex | |
| Intrinsic component of cell outer membrane | The component of the cell outer membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor), which spans or is embedded in one or both leaflets of the membrane. |
| Periplasmic side of cell outer membrane | |
| Intrinsic component of periplasmic side of cell outer membrane | |
| Perivitelline space | The space between the membrane of an oocyte and a surrounding membranous structure (zona pellucida or perivitelline membrane). |
| COPII vesicle coat | One of two multimeric complexes that forms a membrane vesicle coat. COPII is best characterized in S. cerevisiae, where the subunits are called Sar1p, Sec13p, Sec31p, Sec23p, and Sec24p. Vesicles with COPII coats are found associated with endoplasmic reticulum (ER) membranes at steady state. |
| Polyketide synthase complex | A protein complex that carries out enzymatic reactions involved in the biosynthesis of polyketides, any of a diverse group of natural products synthesized via linear poly-beta-ketones. |
| Mitochondrial DNA-directed RNA polymerase complex | |
| ATP-independent citrate lyase complex | |
| Synaptic vesicle membrane | The lipid bilayer surrounding a synaptic vesicle. |
| Complex laminated body | A cytoplasmic inclusion body found in some lateral geniculate neurons and composed of sheets of tubules (25 nm in diameter) separated by dense material (about 75 nm wide), which together with the tubules whorl give a structure resembling a fingerprint. |
| Exocytic vesicle membrane | |
| chaperone-mediated autophagy translocation complex | |
| Extrachromosomal circular DNA | Circular DNA structures that are not part of a chromosome. |
| DNA replication termination region | A chromosomal region that contains fork pausing elements influencing the progression and merging of DNA replication forks. |
| H4/H2A histone acetyltransferase complex | A multisubunit complex that catalyzes the acetylation of histones H4 and H2A. |
| Melanosome membrane | The lipid bilayer surrounding a melanosome. |
| DnaB helicase complex | |
| Filiform apparatus | A complex of cell wall invaginations in a synergid cell, similar to those in transfer cells. |
| Sphere organelle | A nuclear body that is found in the germinal vesicles of amphibian oocytes, and consist of three major parts: a remarkably spherical body about 5-10 pm in diameter, smaller spherical or nearly spherical granules on the surface, and inclusions of various sizes that strongly resemble the surface granules. The parts of the sphere organelle have distinct compositions, including splicing snRNAs and proteins. |
| Eisosome | A cell part that is composed of the eisosome membrane or MCC domain, a furrow-like plasma membrane sub-domain and associated integral transmembrane proteins, and the proteins (eisosome filaments) that form a scaffolding lattice on the cytoplasmic face. Eisosomes broadly affect overall plasma membrane organization. |
| Pigment granule membrane | |
| Laminated body | Inclusion body characterized by regularly spaced sheets of tubules arranged in a whorl pattern resembling a fingerprint. Laminated bodies have been observed in neurons of the lateral geniculate nucleus. |
| Pollen tube tip | The region at growing end of the pollen tube cell, where polarized growth occurs. |
| ATP-binding cassette (ABC) transporter complex | A complex for the transport of metabolites into and out of the cell, typically comprised of four domains; two membrane-associated domains and two ATP-binding domains at the intracellular face of the membrane, that form a central pore through the plasma membrane. Each of the four core domains may be encoded as a separate polypeptide or the domains can be fused in any one of a number of ways into multidomain polypeptides. In Bacteria and Archaebacteria, ABC transporters also include substrate binding proteins to bind substrate external to the cytoplasm and deliver it to the transporter. |
| Radial spoke stalk | Globular portion of the radial spoke that projects towards the central pair of microtubules. |
| SLAC complex | |
| Axonemal outer doublet | |
| Wnt-Frizzled-LRP5/6 complex | |
| Chromocenter | A region in which centric, heterochromatic portions of one or more chromosomes form a compact structure. |
| NuA4 histone acetyltransferase complex | A complex having histone acetylase activity on chromatin, as well as ATPase, DNA helicase and structural DNA binding activities. The complex is thought to be involved in double-strand DNA break repair. Subunits of the human complex include HTATIP/TIP60, TRRAP, RUVBL1, BUVBL2, beta-actin and BAF53/ACTL6A. In yeast, the complex has 13 subunits, including the catalytic subunit Esa1 (homologous to human Tip60). |
| Ferroxidase complex | |
| Cytolytic granule membrane | |
| nitric-oxide synthase complex | |
| laminin-10 complex | A laminin complex composed of alpha5, beta1 and gamma1 polypeptide chains. |
| sucrase-isomaltase complex | A protein complex that possesses oligo-1,6-glucosidase activity; the complex is a heterodimer located in the cell membrane, and is formed by proteolytic cleavage of a single precursor polypeptide. The two subunits have different substrate specificities. |
| Orthogonal array | Square array of closely spaced intramembrane particles, 4-6 nm in size, that form supramolecular aggregates found in the plasma membrane of astrocytes, skeletal muscle and epithelial cells. They have been shown to contain aquaporins (water channels). |
| Chromoplast | A plastid containing pigments other than chlorophyll, usually yellow and orange carotenoid pigments. |
| Myosin VII complex | A myosin complex containing a dimer of class VII myosin heavy chains and associated light chains. Myosin VII (240 kDa) is predicted to be a dimeric molecule with 5 IQ motifs and a tail region with a short stretch of coiled coil followed by two myosin-tail homology (MyTH4) domains, two talin-binding (FERM) domains and an SH3-domain. |
| Ribulose bisphosphate carboxylase complex | A complex containing either both large and small subunits or just small subunits which carries out the activity of producing 3-phosphoglycerate from carbon dioxide and ribulose-1,5-bisphosphate. |
| glutamyl-tRNA(Gln) amidotransferase complex | A protein complex that possesses glutamyl-tRNA(Gln) amidotransferase activity, and therefore creates Gln-tRNA by amidating Glu-tRNA; usually composed of 3 subunits: A, B, and C. Note that the C subunit may not be required in all organisms. |
| Spectrosome | A germline specific spherical organelle, rich in membrane skeletal proteins. Precursor to the fusome. |
| Conoid | A spiral cytoskeletal structure located at the apical end of the apical complex in some apicomplexan parasites. Fibers form a left-handed spiral, and are comprised of tubulin protofilaments organized in a ribbon-like structure that differs from the conventional tubular structure characteristic of microtubules. |
| Hyaluranon cable | A cable structure, surrounding some cell types (e.g. proximal or bronchial tubular epithelial cells), and composed of hyaluranon (HA), a ubiquitous connective tissue glycosaminoglycan. |
| CD95 death-inducing signaling complex | A protein complex formed upon binding of Fas/CD95/APO-1 to its ligand. The complex includes FADD/Mort1, procaspase-8/10 and c-FLIP in addition to the ligand-bound receptor. |
| Basal cortex | The region that lies just beneath the plasma membrane on the basal edge of a cell. |
| Extracellular isoamylase complex | |
| Plasmodesma | A fine cytoplasmic channel, found in all higher plants, that connects the cytoplasm of one cell to that of an adjacent cell. |
| C bouton | Synaptic bouton found in spinal cord on the soma and proximal dendrites of motor neurons. |
| Early phagosome | A membrane-bounded intracellular vesicle as initially formed upon the ingestion of particulate material by phagocytosis. |
| cation-transporting ATPase complex | Protein complex that carries out the reaction: ATP + H2O + cation(out) = ADP + phosphate + cation(in). |
| Amyloplast | A plastid whose main function is to synthesize and store starch. |
| Sulfate adenylyltransferase complex (ATP) | |
| Galectin lattice | |
| PYM-mago-Y14 complex | |
| Apicoplast | The plastid organelle found in apicomplexans. |
| Perisynaptic space | |
| chromosome, subtelomeric region | |
| BRCA1-B complex | A protein complex that contains the BRCA1-BARD1 heterodimer, BACH1 and TopBP1, and binds to DNA during S phase at DNA damage sites. |
| Schmidt-Lanterman incisure | Regions within compact myelin in which the cytoplasmic faces of the enveloping myelin sheath are not tightly juxtaposed, and include cytoplasm from the cell responsible for making the myelin. Schmidt-Lanterman incisures occur in the compact myelin internode, while lateral loops are analogous structures found in the paranodal region adjacent to the nodes of Ranvier. |
| Bfa1-Bub2 complex | |
| CUGBP1-eIF2 complex | A protein complex that contains the eukaryotic translation initiation factor 2 complex (EIF2), CUG binding protein 1, and several endoplasmic reticulum proteins; the complex is involved in the regulation of translation. |
| Basal dendrite | |
| Amino acid transport complex | |
| exon-exon junction subcomplex mago-y14 | |
| Rod spherule | A specialized neuron projection which is the site of synaptic transmission produced by retinal rod cells. Rod spherules are small round enlargements of the axon (3-5 micrometers diameter) or even extensions of the cell body. |
| Cell tip | The region at either end of the longest axis of a cylindrical or elongated cell. |
| Xylanosome | |
| GTPase activator complex | |
| Stromule | Thin filamentous structure extending from the surface of all plastid types examined so far, including chloroplast, proplastid, etioplast, leucoplast, amyloplast, and chromoplast. In general, stromules are more abundant in tissues containing non-green plastids, and in cells containing smaller plastids. The primary function of stromules is still unresolved, although the presence of stromules markedly increases the plastid surface area, potentially increasing transport to and from the cytosol. Other functions of stromules, such as transfer of macromolecules between plastids and starch granule formation in cereal endosperm, may be restricted to particular tissues and cell types. |
| Polarisome | Protein complex that plays a role in determining cell polarity by directing the localized assembly of actin filaments at polarization sites; in Saccharomyces the polarisome includes Bni1p, Spa2p, Pea2p, and Bud6p. |
| Adventitious septum | |
| Spine apparatus | A specialization of the endomembrane system found in some classes of neuron spines consisting of two or more closely apposed lamellae with interspersed dense material. |
| 9+0 motile cilium | |
| ER to Golgi transport vesicle membrane | The lipid bilayer surrounding a vesicle transporting substances from the endoplasmic reticulum to the Golgi. |
| Lamellar body membrane | The lipid bilayer surrounding a lamellar body. A lamellar body is a membrane-bounded organelle, specialized for the storage and secretion of various substances (surfactant phospholipids, glycoproteins and acid phosphates) which are arranged in the form of tightly packed, concentric, membrane sheets or lamellae. Has some similar properties to, but is distinct from, a lysosome. |
| Sperm connecting piece | The segment of the sperm flagellum that attaches to the implantation fossa of the nucleus in the sperm head; from the remnant of the centriole at this point, the axoneme extends throughout the length of the flagellum. |
| Micronucleus | A membrane-bounded organelle of ciliated protozoan cells that contains a diploid copy of the cell's complete genome. Sections of contiguous sequence in the macronucleus are often interrupted by internal eliminated sequences (IES), and may be permuted, in micronuclei. Genic transcription is not found in micronuclei. Some ciliate species may contain multiple micronuclei per cell. |
| M/G1 phase-specific MADS box-forkhead transcription factor complex | |
| Vacuolar HOPS complex | |
| Growing cell tip | The region at either end of the longest axis of a cylindrical or elongated cell, where polarized growth occurs. |
| Longitudinal sarcoplasmic reticulum | The portion of the free sarcoplasmic reticulum consisting of longitudinal tubules that connect terminal cisternae. |
| Wnt signalosome | |
| Blood microparticle | A phospholipid microvesicle that is derived from any of several cell types, such as platelets, blood cells, endothelial cells, or others, and contains membrane receptors as well as other proteins characteristic of the parental cell. Microparticles are heterogeneous in size, and are characterized as microvesicles free of nucleic acids. |
| cAMP-dependent protein kinase complex | An enzyme complex, composed of regulatory and catalytic subunits, that catalyzes protein phosphorylation. Inactive forms of the enzyme have two regulatory chains and two catalytic chains; activation by cAMP produces two active catalytic monomers and a regulatory dimer. |
| Kinesin I complex | A complex of two kinesin heavy chains and two kinesin light chains. |
| Interstitial matrix | A type of extracellular matrix found in interstitial connective tissue, characterized by the presence of fibronectins, proteoglycans, and types I, III, V, VI, VII and XII collagens. |
| ANPR-A receptor complex | |
| Axonemal microtubule | A microtubule in the axoneme of a eukaryotic cilium or flagellum; an axoneme contains nine modified doublet microtubules, which may or may not surround a pair of single microtubules. |
| Chitosome | An intracellular membrane-bounded particle found in fungi and containing chitin synthase; it synthesizes chitin microfibrils. Chitin synthase activity exists in chitosomes and they are proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum. |
| Linear element | A proteinaceous scaffold associated with S. pombe chromosomes during meiotic prophase. Linear elements have a structure related to but not equivalent to the synaptonemal complex. |
| Stereocilia ankle link | A stereocilia coupling link that is composed of a fine filament present in developing stereocilia that couples the bases of individual stereocilia to one another. They are not present in mature stereocilia. |
| Stereocilia ankle link complex | A complex of proteins that connect growing stereocilia in developing cochlear hair cells, composed of Vlgr1, usherin, vezatin, and whirlin. |
| Heavy chain immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of the IgNAR isotype held together by disulfide bonds and lacking immunoglobulin light chains. |
| Spine synapse | |
| EFF-1 complex | |
| Intracellular cyclic nucleotide activated cation channel complex | A protein complex that forms a transmembrane channel through which cations ions may pass in response to an intracellular cyclic nucleotide binding to the channel complex or one of its constituent parts. |
| Mating projection | The projection formed by unicellular fungi in response to mating pheromone. |
| Bilobe structure | |
| Plastid stroma | The proteinaceous ground substance of plastids. |
| Epididymosome | |
| Mitochondrial pyruvate dehydrogenase complex | Complex that carries out the oxidative decarboxylation of pyruvate to form acetyl-CoA in eukaryotes; includes subunits possessing three catalytic activities: pyruvate dehydrogenase (E1), dihydrolipoamide S-acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). The This Eukaryotic form usually contains more subunits than its bacterial counterpart; for example, one known complex contains 30 E1 dimers, 60 E2 monomers, and 6 E3 dimers as well as a few copies of pyruvate dehydrogenase kinase and pyruvate dehydrogenase phosphatase. |
| nucleus-vacuole junction | An organelle membrane contact site formed between the vacuole membrane and the outer nuclear membrane. In S. cerevisiae these contacts are mediated through direct physical interaction between Vac8p and Nvj1p. |
| TRAIL death-inducing signaling complex | A protein complex formed upon binding of TRAIL to its ligand. The complex includes FADD/Mort1 and procaspase-8 addition to the ligand-bound receptor. |
| Interphotoreceptor matrix | A specialized extracellularc matrix that surrounds the photoreceptors of the retina and lies between them and the apical surface of the retinal pigment epithelium. The IPM has been implicated in several important activities required for photoreceptor function and maintenance. |
| Mesaxon | Portion of the ensheathing process (either myelin or non-myelin) where the enveloping lips of the ensheathing cell come together so that their apposed plasma membranes run parallel to each other, separated by a cleft 12 nm wide. |
| Arciform density | |
| Macropinosome | A membrane-bounded, uncoated intracellular vesicle formed by the process of macropinocytosis. |
| Symplast | The interconnected cell membranes and intracellular regions of a plant. The interconnections occur via the plasmodesmata. |
| Amphisome | An autophagic vacuole formed upon fusion between autophagosomes and endosomes. |
| Photosystem II antenna complex | The antenna complex of photosystem II. A photosystem has two closely linked components, an antenna containing light-absorbing pigments and a reaction center. Each antenna contains one or more light-harvesting complexes (LHCs). |
| Equatorial microtubule organizing center | A microtubule organizing center formed by a band of gamma-tubulin that is recruited to a circumferential band of F-actin at the midpoint of a cell and which nucleates microtubules from the cell division site at the end of mitosis. |
| Haustorium | A projection from a cell or tissue that penetrates the host's cell wall and invaginates the host cell membrane. |
| PHA granule | An inclusion body located in the cytoplasm that consists of polyhydroxyalkanoate (PHA) molecules and associated proteins, surrounded by a phospholipid monolayer; the proteins include PHA synthase, PHA depolymerase and 3HB-oligomer hydroxylase, phasins (PhaPs), which are thought to be the major structural proteins of the membrane surrounding the inclusion, and the regulator of phasin expression PhaR. |
| m-AAA complex | Protease complex of the mitochondrial inner membrane that is involved in mitochondrial protein turnover and in processing of proteins imported into mitochondria. |
| FtsBL complex | |
| Mitosome | A double-membrane-bounded organelle that functions in iron-sulfur protein maturation; evolutionarily derived from mitochondria. The mitosome has been detected only in anaerobic or microaerophilic organisms that do not have mitochondria, such as Entamoeba histolytica, Giardia intestinalis and several species of Microsporidia. These organisms are not capable of gaining energy from oxidative phosphorylation, which is normally performed by mitochondria. |
| interleukin-9 receptor complex | A protein complex that binds interleukin-9; comprises an alpha and a beta subunit. The alpha chain is specific to the interleukin-9 receptor, whereas the beta chain is shared with the receptors for several other interleukins. |
| Proteasome storage granule | A multisubunit proteasome complex that localizes in the cytoplasm as dot-like structures when cells are in a quiescent state. |
| H zone | A relatively pale zone traversing the center of the A band of a sarcomere, visible in relaxed muscle fibers; consists of the central portion of thick (myosin) filaments that are not overlapped by thin (actin) filaments. |
| CTDK-1 complex | |
| Cell pole | Either of two different areas at opposite ends of an axis of a cell. |
| Pinosome | A membrane-bounded, uncoated intracellular vesicle formed by the process of pinocytosis. |
| ATPase dependent transmembrane transport complex | A transmembrane protein complex that functions in ATPase dependent active transport across a membrane. |
| Nucleolar chromatin | The portion of nuclear chromatin associated with the nucleolus; includes the DNA encoding the ribosomal RNA. |
| Symmetric synapse | A type of synapse occurring primarily on dendrite shafts and neuronal cell bodies. Symmetric synapses involve axons containing clusters of predominantly flattened or elongated vesicles and do not contain a prominent postsynaptic density. |
| Ensheathing process | A cell projection (often from glial cells such as Schwann cells) that surrounds an unmyelinated axon or cell soma. |
| Intracellular ferritin complex | A ferritin complex located in the cell. Intracellular ferritin complexes contain 24 subunits, in a mixture of L (light) chains and H (heavy) chains. |
| Smooth endoplasmic reticulum | The smooth endoplasmic reticulum (smooth ER or SER) has no ribosomes attached to it. The smooth ER is the recipient of the proteins synthesized in the rough ER. Those proteins to be exported are passed to the Golgi complex, the resident proteins are returned to the rough ER and the lysosomal proteins after phosphorylation of their mannose residues are passed to the lysosomes. Glycosylation of the glycoproteins also continues. The smooth ER is the site of synthesis of lipids, including the phospholipids. The membranes of the smooth ER also contain enzymes that catalyze a series of reactions to detoxify both lipid-soluble drugs and harmful products of metabolism. Large quantities of certain compounds such as phenobarbital cause an increase in the amount of the smooth ER. |
| syndecan-syntenin-ALIX complex | |
| Dendritic spine neck | Part of the dendritic spine that connects the dendritic shaft to the head of the dendritic spine. |
| U12-type spliceosomal complex | Any spliceosomal complex that forms during the splicing of a messenger RNA primary transcript to excise an intron; the series of U12-type spliceosomal complexes is involved in the splicing of the majority of introns that contain atypical AT-AC terminal dinucleotides, as well as other non-canonical introns. The entire splice site signal, not just the terminal dinucleotides, is involved in determining which spliceosome utilizes the site. |
| Respiratory chain complex I | Respiratory chain complex I is an enzyme of the respiratory chain. It consists of several polypeptide chains and is L-shaped, with a horizontal arm lying in the membrane and a vertical arm that projects into the matrix. The electrons of NADH enter the chain at this complex. |
| Mucin granule | A secretory granule that contains mucin. |
| Gemini of coiled bodies | Nuclear bodies frequently found near or associated with Cajal bodies (also called coiled bodies or CBs). Gemini of coiled bodies, or 'gems', are similar in size and shape to CBs, and often indistinguishable under the microscope. Unlike CBs, gems do not contain small nuclear ribonucleoproteins (snRNPs); they contain a protein called survivor of motor neurons (SMN) whose function relates to snRNP biogenesis. Gems are believed to assist CBs in snRNP biogenesis, and to play a role in the etiology of spinal muscular atrophy (SMA). |
| I(KACh) inward rectifier potassium channel complex | |
| Mitotic checkpoint complex, CDC20-MAD2 subcomplex | |
| methyl-tetrahydromethanopterin:coenzyme M methyltransferase complex | A protein complex consisted of eight polypeptides. This complex catalyzes the formation of methyl-coenzyme M and H4MPT from N5-methyl-H4MPT and CoM during methanogenesis. |
| egasyn-beta-glucuronidase complex | A protein complex that contains beta-glucuronidase and the carboxyl esterase egasyn; formation of the complex causes beta-glucuronidase to be retained in the endoplasmic reticulum. |
| Methyl accepting chemotaxis protein complex | |
| titin-telethonin complex | |
| Subapical complex | The most apical region of the lateral plasma membrane of an invertebrate epithelial cell. The subapical complex lies above the zonula adherens and the septate junction, and is comparable to the position of the tight junction of vertebrate cells. |
| Lower tip-link density | |
| Myosin IX complex | |
| U2-type catalytic step 1 spliceosome | A spliceosomal complex that is formed by the displacement of the U1 and U4 snRNPs from the precatalytic spliceosome; the U2, U5 and U6 snRNPs remain associated with the mRNA. This complex, sometimes called the activated spliceosome, is the catalytically active form of the spliceosome, and includes many proteins in addition to those found in the U2, and U5 and U6 snRNPs. |
| Glucosidase complex | A protein complex which is capable of glucosidase activity. |
| Zonula adherens | A cell-cell adherens junction which forms a continuous belt near the apex of epithelial cells. |
| Rhino-Deadlock-Cutoff Complex | |
| Classical Lewy body | Cytoplasmic inclusion, 5 to 15 micrometers in diameter, with a dense core surrounded by a halo of 10 to 20 nm wide radially oriented alpha-synuclein fibrils. |
| Vps55/Vps68 complex | |
| Cardiac myofibril | |
| U4atac/U6atac x U5 tri-snRNP complex | |
| TAM protein secretion complex | |
| DnaA-DiaA complex | |
| PNGase complex | |
| Old cell pole | |
| Male pronucleus | The pronucleus originating from the spermatozoa that was involved in fertilization. |
| Ciliary transition fiber | A nine-bladed, propeller-like protein complex that links the distal end of the basal body and the cilium to the plasma membrane. Functions in protein sorting and gating (i.e. active and passive transport of proteins in and out of the cilium). |
| Median body | |
| Mitochondrial cloud | A prominent mass in the cytoplasm of previtellogenic oocytes. The cloud contains both mitochondria and electron-dense granulofibrillar material (GFM) and is the source of germinal granule material. |
| Heterochromatin domain | |
| Cyclin K-CDK12 complex | A protein complex consisting of cyclin Kand cyclin-dependent kinase 12 (CDK12). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Type I pilus | |
| Cry-Per complex | |
| MHC class I protein complex | A transmembrane protein complex composed of a MHC class I alpha chain and an invariant beta2-microglobin chain, and with or without a bound peptide antigen. Class I here refers to classical class I molecules. |
| Multivesicular body membrane | The lipid bilayer surrounding a multivesicular body. |
| Pseudopodium | A temporary cytoplasmic extrusion by means of which an ameba or other ameboid organism or cell moves about or engulfs food. |
| laminin-4 complex | A laminin complex composed of alpha2, beta2 and gamma1 polypeptide chains. |
| Primosome complex | Any of a family of protein complexes that form at the origin of replication and function in replication restart in all organisms. Early complexes initiate double-stranded DNA unwinding. The core unit consists of a replicative helicase and a primase. The helicase further unwinds the DNA and recruits the polymerase machinery. The primase synthesizes RNA primers that act as templates for complementary stand replication by the polymerase machinery. The primosome contains a number of associated proteins and protein complexes and is part of the replication initiation process. |
| Split septin rings | |
| Ring centriole | |
| TRAPPII protein complex | A complex that mediates intra-Golgi traffic, Golgi exit, endosome-to-Golgi traffic, and the trafficking of autophagy proteins from Golgi to the pre-autophagosomal structure. Binds to a component of the COPI coat. In yeast it includes the following subunits: Bet3 (as homodimer), Bet5, Tca17, Trs20, Trs23, Trs31, Trs33, Trs65, Tr120, Tr130. The whole complex is thought to dimerize with itself. |
| SCF-Cdc4 ubiquitin ligase complex | |
| Mononeme | |
| Biotin carboxylase complex | |
| Late recombination nodule | An electron dense structure that is associated with meiotic chromosomes in pachytene during meiosis I. |
| IgD immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgD immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| plastid-encoded plastid RNA polymerase complex | An RNA polymerase complex containing polypeptides encoded by the plastid genome. Plastid-encoded DNA-directed RNA polymerases resemble eubacterial multisubunit RNA polymerases, with a core composed of alpha, beta, and beta-prime subunits. Some forms contain multiple additional subunits. An additional sigma factor subunit is required for promoter recognition. |
| Phagocytic vesicle membrane | The lipid bilayer surrounding a phagocytic vesicle. |
| IgE B cell receptor complex | An IgE immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of the IgE isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| Dopaminergic synapse | |
| Mitochondrial proton-transporting ATP synthase complex | A proton-transporting ATP synthase complex found in the mitochondrial membrane. |
| Myosin II filament | A bipolar filament composed of myosin II molecules. |
| H-NS complex | |
| Cortical microtubule | Arrays of microtubules underlying and connected to the plasma membrane in the cortical cytosol. |
| Phragmoplast | Fibrous structure (light microscope view) that arises between the daughter nuclei at telophase and within which the initial partition (cell plate), dividing the mother cell in two (cytokinesis), is formed. Appears at first as a spindle connected to the two nuclei, but later spreads laterally in the form of a ring. Consists of microtubules. |
| Dimeric ribonuclease P complex | |
| Microvillus membrane | The portion of the plasma membrane surrounding a microvillus. |
| Taurine dioxygenase complex | |
| Extrinsic component of intraperoxisomal membrane | The component of the intraperoxisomal membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| bacterial-type flagellum filament cap | |
| Nuclear pore nuclear basket | A filamentous, cage-like assembly on the nuclear face of the nuclear pore complex (NPC). In S. cerevisiae, Mlp1p and Mlp2p are two major components of the NPC nuclear basket. In vertebrates, Tpr is a major component. |
| IgD B cell receptor complex | An IgD immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| Telomerase catalytic core complex | The minimal catalytic core of telomerase is a ribonucleoprotein complex composed of a catalytic reverse transcriptase subunit and an RNA subunit that provides the template for telomeric DNA addition. |
| Endolysosome membrane | The lipid bilayer surrounding an endolysosome. An endolysosome is a transient hybrid organelle formed by fusion of a late endosome with a lysosome. |
| Cyclin E2-CDK2 complex | A protein complex consisting of cyclin E2 and cyclin-dependent kinase 2 (CDK2). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Perinuclear region of cytoplasm | Cytoplasm situated near, or occurring around, the nucleus. |
| Cellular bud neck | The constriction between the mother cell and daughter cell (bud) in an organism that reproduces by budding. |
| Internode region of axon | An axon part that is located between the nodes of Ranvier and surrounded by compact myelin sheath. |
| Shc-Grb2-Sos complex | A protein complex that contains Grb2, the adaptor protein Shc and the guanine nucleotide exchange factor Sos (or an ortholog thereof, such as mSos1), and is involved in linking EGFR activation to the p21-Ras pathway. |
| RNA nuclear export complex | A complex which usually consists of three components, e.g. in Xenopus and yeast, the export receptor CRM1 (also known as exportin 1), the Ran protein and any RNA with a nuclear export sequence (NES). The complex acts to export RNA molecules with a NES from the nucleus through a nuclear pore. |
| PAT complex | |
| Toc complex | Protein translocon complex at the chloroplast outer membrane. |
| Central element | A structural unit of the synaptonemal complex found between the lateral elements. |
| FtsQBL complex | |
| Perichromatin fibrils | Structures of variable diameter visible in the nucleoplasm by electron microscopy, mainly observed near the border of condensed chromatin. The fibrils are enriched in RNA, and are believed to be sites of pre-mRNA splicing and polyadenylylation representing the in situ form of nascent transcripts. |
| Extrachromosomal DNA | DNA structures that are not part of a chromosome. |
| EDS1 disease-resistance complex | |
| Meiotic spindle | A spindle that forms as part of meiosis. Several proteins, such as budding yeast Spo21p, fission yeast Spo2 and Spo13, and C. elegans mei-1, localize specifically to the meiotic spindle and are absent from the mitotic spindle. |
| Translation repressor complex | |
| Golgi lumen | The volume enclosed by the membranes of any cisterna or subcompartment of the Golgi apparatus, including the cis- and trans-Golgi networks. |
| Uropod | A membrane projection with related cytoskeletal components at the trailing edge of a cell in the process of migrating or being activated, found on the opposite side of the cell from the leading edge or immunological synapse, respectively. |
| Cell trailing edge | The area of a motile cell opposite to the direction of movement. |
| Cellular bud | A protuberance from a cell of an organism that reproduces by budding, which will grow larger and become a separate daughter cell after nuclear division, cytokinesis, and cell wall formation (when appropriate). The daughter cell may completely separate from the mother cell, or the mother and daughter cells may remain associated. |
| Microvillar actin bundle | |
| Commitment complex | A spliceosomal complex that is formed by association of the U1 snRNP with the 5' splice site of an unspliced intron in an RNA transcript. |
| Iridosome | A tissue-specific, membrane-bounded cytoplasmic organelle within which purines crystalize in reflective stacks. Iridosomes are synthesized in iridophore cells and are silver, gold or iridescent in appearance. |
| Nuclear proteasome complex | A proteasome found in the nucleus of a cell. |
| Retrograte transporter complex, Golgi to ER | |
| Sperm plasma membrane | |
| U11/U12 snRNP | A ribonucleoprotein complex formed by the association of the U11 and U12 small nuclear ribonucleoproteins. |
| Ciliary necklace | |
| ASTRA complex | A protein complex that is part of the chromatin remodeling machinery; the acronym stands for ASsembly of Tel, Rvb and Atm-like kinase. In Saccharomyces cerevisiae this complex includes Rvb1p, Rvb2p, Tra1p, Tel2p, Asa1p, Ttilp and Tti2p. |
| Actin filament bundle of actin-based cell projection | |
| Compound sieve plate | |
| Cytoneme | A long, thin, polarized cell projection that contains actin and can extend for distances many times the diameter of the cell. Cytonemes represent extensions of cell cytoplasm and typically have a diameter of approximately 0.2um. |
| Supraspliceosomal complex | Multicomponent complex of RNA and proteins that is composed of four active spliceosomes, termed native spliceosomes, connected to each other by the pre-mRNA. The supraspliceosome is the nuclear machine where the pre-mRNA processing takes place, like the 5'-end capping, 3'-end cleavage, splicing and editing. |
| Glyoxysome | A specialized form of peroxisome that contains the enzymes of the glyoxylate pathway. The glyoxysome is found in some plant cells, notably the cells of germinating seeds. |
| Acroblast | A cone-shaped structure in the head of a spermatozoon, which is formed by the coalescence of Golgi fragments following the completion of meiosis. The acroblast is situated adjacent to the acrosomal vesicle. |
| catenin-TCF7L2 complex | A protein complex that contains a catenin and TCF7L2 (TCF4), binds to the TCF DNA motif within a promoter element, and is involved in the regulation of WNT target gene transcription. |
| beta-catenin-TCF7L2 complex | A protein complex that contains beta-catenin and TCF7L2 (TCF4), binds to the TCF DNA motif within a promoter element, and is involved in the regulation of WNT target gene transcription. |
| tRNA-specific adenosine-34 deaminase complex | |
| Presynaptic density | |
| Histone H3-K14 acetyltransferase complex | |
| Aleurone grain membrane | The lipid bilayer surrounding an aleurone grain. |
| Extrinsic component of synaptic vesicle membrane | |
| RNA polymerase I core factor complex | A RNA polymerase I-specific transcription factor complex that is required for the transcription of rDNA by RNA polymerase I. In yeast the complex consists of Rrn6p, Rrn7p, and Rrn11p. |
| Chloroplast stroma | The space enclosed by the double membrane of a chloroplast but excluding the thylakoid space. It contains DNA, ribosomes and some temporary products of photosynthesis. |
| PAN complex | A complex that possesses poly(A)-specific ribonuclease activity; catalyzes the message-specific shortening of mRNA poly(A) tails. Contains at least two subunits, known as Pan2p and Pan3p in Saccharomyces. |
| I-kappaB/NF-kappaB complex | A protein complex containing an inhibitory-kappaB (I-kappaB/IKB) protein and one or more copies of an NF-kappaB protein. In the resting state, NF-kappaB dimers are bound to I-kappaB proteins, sequestering NF-kappaB in the cytoplasm. |
| cis-Golgi network | The network of interconnected tubular and cisternal structures located at the convex side of the Golgi apparatus, which abuts the endoplasmic reticulum. |
| IHF-DNA complex | |
| CAAX-protein geranylgeranyltransferase complex | A heterodimeric enzyme, composed of an alpha and a beta subunit. Participates in the post-translational C-terminal modification of several small GTPases, allowing their targeting to the membrane. |
| Bleb | A cell extension characterized by rapid formation, rounded shape, and scarcity of organelles within the protrusions. |
| Macronucleus | A membrane-bounded organelle of ciliated protozoan cells that contains polyploid copies of a portion of the cell's complete genome. Transcription of genes occurs in macronuclei. Some ciliate species may contain multiple macronuclei per cell. |
| Arbuscule | Highly branched symbiont haustoria within host root cortex cells, responsible for nutrient exchange. |
| ER ubiquitin ligase complex | A ubiquitin ligase complex found in the ER. |
| Primary dendrite | |
| Nuclear microtubule | Any microtubule in the nucleus of a cell. |
| Multiple synapse bouton | |
| Histone mRNA stem-loop binding complex | |
| Parallel actin filament bundle | |
| mRNA cap methyltransferase complex | A protein complex that consists of an RNA 5' triphosphatase and a guanyl transferase (Cet1p and Ceg1p in S. cerevisiae; Pct1 and Ceg1 in S. pombe) and is involved in mRNA capping. |
| Carbon phosphorus lyase complex | |
| Basolateral plasma membrane | The region of the plasma membrane that includes the basal end and sides of the cell. Often used in reference to animal polarized epithelial membranes, where the basal membrane is the part attached to the extracellular matrix, or in plant cells, where the basal membrane is defined with respect to the zygotic axis. |
| IgW immunoglobulin complex | |
| Dinoflagellate epicone | |
| post-mRNA release spliceosomal complex | A spliceosomal complex that is formed following the release of the spliced product from the post-spliceosomal complex and contains the excised intron and three snRNPs, including U5. |
| Translation preinitiation complex | A ribonucleoprotein complex that contains the small ribosomal subunit, a translation initiation ternary complex (i.e. an initiator tRNA, GTP, and an IF2 or eIF2 complex), and an mRNA. |
| Medial cortex | A medial cortical band overlaying the nucleus which acts as a landmark for contractile ring positioning and plays a role in cell cycle regulation. |
| ER body | A novel compartment found in plant cells that is derived from the ER. The structures have a characteristic shape and size (10 mm long and 0.5 mm wide) and are surrounded with ribosomes. They have been found in Arabidopsis thaliana and related Brassicaceae species. |
| Annulate lamellae | Stacks of endoplasmic reticulum (ER) membranes containing a high density of nuclear pores, thought to form from excess nuclear membrane components, that have been described in a number of different cells. Annulate lamellar membranes are continuous with and embedded within the ER. |
| FANCM-MHF complex | A protein complex contains the proteins FANCM and MHF, or their orthologs, plays an essential role in DNA remodeling, protects replication forks, and is conserved in eukaryotes. |
| Mst2 histone acetyltransferase complex | |
| Serotonergic synapse | |
| Synaptic vesicle, resting pool | |
| Transnitrosylase complex | |
| Woronin body | |
| Insulin control element activator complex | |
| Glycosome | A membrane-bounded organelle found in organisms from the order Kinetoplastida that houses the enzymes of glycolysis. |
| sodium:potassium-exchanging ATPase complex | Sodium:potassium-exchanging ATPases are tetrameric proteins, consisting of two large alpha subunits and two smaller beta subunits. The alpha subunits bear the active site and penetrate the membrane, while the beta subunits carry oligosaccharide groups and face the cell exterior. |
| Dendritic filopodium | |
| Smp focus | |
| T-bar | |
| archaeal-type flagellum | |
| GET complex | A multisubunit complex involved in ER/Golgi trafficking (Golgi to ER Traffic). In yeast, includes Get1p, Get2p and Get3p proteins. |
| Muscle myosin complex | A filament of myosin found in a muscle cell of any type. |
| trans-synaptic protein complex | |
| atf1-pcr1 complex | |
| Cyclin E1-CDK2 complex | A protein complex consisting of cyclin E1 and cyclin-dependent kinase 2 (CDK2). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Sex chromatin | Chromatin that is part of a sex chromosome. |
| Mitochondrial electron transfer flavoprotein complex | A protein complex located in the mitochondrion. It contains flavin adenine dinucleotide (FAD) that, together with an acyl-CoA dehydrogenase, forms a system that oxidizes an acyl-CoA molecule and reduces ubiquinone and other acceptors in the mitochondrial electron transport system. |
| SHREC complex | A histone deacetylase complex that contains a core of four proteins -- Clr1, Clr2, Clr3, and Mit1 in fission yeast -- and localizes to all heterochromatic regions in the genome as well as some euchromatic sites. The complex is involved in regulating nucleosome positioning to assemble higher-order chromatin structures. |
| dolichyl-phosphate-mannose-protein mannosyltransferase complex | |
| Molybdopterin synthase complex | A protein complex that possesses molybdopterin synthase activity. In E. coli, the complex is a heterotetramer consisting of two MoaD and two MoaE subunits. |
| S-layer | A crystalline protein layer surrounding some bacteria. |
| sub-surface cisterna | Specialization of the hypolemmal cisterna consisting of either single profiles or closely apposed stacks of endoplasmic reticulum in which the lumen is obliterated, lying 10-20 nm beneath the plasma membrane. |
| Telodendria | |
| Myosin V complex | A myosin complex containing a dimer of class V myosin heavy chains and associated light chains; involved in intracellular transport. Myosin V is a dimeric molecule consisting of conserved motor domains followed by 6 IQ motifs which bind specific light chains and calmodulin. The tail domain is important for cellular localization and cargo binding and can be divided into an alpha-helical coiled coil region and a C-terminal globular region. |
| TAT protein transport complex | A complex of three proteins integral to the cytoplasmic membrane of bacteria and membranes of organelles derived from bacteria (chloroplasts and mitochondria) involved in membrane transport of folded proteins. |
| Nuclear MIS12/MIND complex | A multiprotein kinetochore subcomplex that binds to centromeric chromatin and forms part of the inner kinetochore of a chromosome in the nucleus. It helps to recruit outer kinetochore subunits that will bind to microtubules. Nuclear localization arises in some organisms because the nuclear envelope is not broken down during mitosis. In S. cerevisiae, it consists of at least four proteins: Mtw1p, Nnf1p, Nsl1p, and Dsn1. |
| Mitochondrial iron-sulfur cluster assembly complex | |
| plastid-encoded plastid RNA polymerase complex A | A plastid-encoded DNA-directed RNA polymerase complex that resembles eubacterial multisubunit RNA polymerases, with a core composed of alpha, beta, and beta-prime subunits. An additional subunit, a sigma factor, is required for promoter recognition. PEP-A is generated from the PEP-B form during chloroplast maturation to generate a complex composed of at least thirteen polypeptides that is not sensitive to the antibiotic rifampicin, like its precursor form the PEP-B complex. |
| Hypolemmal cisterna | Specialized part of the smooth endoplasmic reticulum that closely underlies the plasma membrane, usually within 60 nm or closer. |
| AnxA2-p11 complex | |
| tRNA (m2G10) methyltransferase complex | |
| Smooth endoplasmic reticulum cisterna | |
| Endoplasmic reticulum cisternal network | |
| Bre1-Rad6 ubiquitin ligase complex | |
| penta-snRNP complex | |
| Cell plate | The nascent cell membrane and cell wall structure that forms between two daughter nuclei near the center of a dividing plant cell. It develops at the equitorial region of the phragmoplast. It grows outwards to join with the lateral walls and form two daughter cells. |
| Acetolactate synthase complex | |
| Cytosolic proteasome complex | A proteasome complex found in the cytosol of a cell. |
| mitochondrion-derived vesicle | |
| Presynaptic periactive zone | A region that surrounds the active zone of the presynaptic plasma membrane, and is specialized for the control of synaptic development. |
| eRF1 methyltransferase complex | |
| U4atac/U6atac snRNP | A ribonucleoprotein complex that contains base-paired U4atac and U6atac small nuclear RNAs. |
| Bacterial nucleoid | The region of a bacterial cell to which the DNA is confined. |
| Interphase microtubule organizing center | A microtubule organizing center found in interphase cells, which organize a longitudinal array of three to five MT bundles from the nuclear envelope during interphase. Each MT bundle is composed of two to seven MTs arranged in an antiparallel configuration, with the dynamic MT plus ends extending toward the cell tips and stable minus ends near the nucleus. |
| Aspartate carbamoyltransferase complex | |
| Mannan polymerase complex | |
| Symbiosome | A double-enveloped cell compartment, composed of an endosymbiont with its plasmalemma (as inner envelope) and a non-endosymbiotic outer envelope (the perisymbiontic membrane). |
| Apical tubulobulbar complex | |
| Replication inhibiting complex | |
| Plastid acetyl-CoA carboxylase complex | An acetyl-CoA carboxylase complex located in the stroma of a plastid. |
| Microtubule bundle | An arrangement of closely apposed microtubules running parallel to each other. |
| Methane monooxygenase complex | A protein complex that possesses methane monooxygenase activity; dimeric and trimeric complexes have been characterized. |
| cyclic-nucleotide phosphodiesterase complex | |
| TRAPPIII protein complex | A complex that functions in anterograde transport at the Golgi and also regulates autophagy. In yeast it includes at least the following subunits: Bet3 (as homodimer), Bet5, Trs20, Trs23, Trs31, Trs33, Trs85. TRAPPIII may include further, as yet undescribed, proteins. |
| Complement component C1 complex | A protein complex composed of six subunits of C1q, each formed of the three homologous polypeptide chains C1QA, C1QB, and C1QB, and tetramer of two C1QR and two C1QS polypeptide chains. |
| plus-end kinesin complex | Any complex that includes a dimer of molecules from the kinesin superfamily and any associated proteins, and moves towards the plus end of a microtubule. |
| Cobalamin transport complex | |
| Barr body | A structure found in a female mammalian cell containing an unpaired X chromosome that has become densely heterochromatic, silenced and localized at the nuclear periphery. |
| Platelet alpha granule membrane | The lipid bilayer surrounding the platelet alpha granule. |
| Basal plasma membrane | The region of the plasma membrane located at the basal end of the cell. Often used in reference to animal polarized epithelial membranes, where the basal membrane is the part attached to the extracellular matrix, or in plant cells, where the basal membrane is defined with respect to the zygotic axis. |
| Cyclin A1-CDK2 complex | A protein complex consisting of cyclin A1 and cyclin-dependent kinase 2 (CDK2). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Nuclear dicing body | A small round nuclear body, measuring 0.2-0.8 microns in diameter that is diffusely distributed throughout the nucleoplasm. Several proteins known to be involved in miRNA processing have been localized to these structures. D-bodies are thought to be involved in primary-miRNA processing and/or storage/assembly of miRNA processing complexes. |
| Extrinsic component of mitochondrial outer membrane | The component of a mitochondrial outer membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| succinate-CoA ligase complex (ADP-forming) | A heterodimeric enzyme complex, composed of an alpha and beta chain, most usually found in (but not limited to) bacteria. Functions in the TCA cycle, hydrolyzing succinyl-CoA into succinate and CoA, thereby forming ATP. |
| Translation release factor complex | A heterodimeric complex involved in the release of a nascent polypeptide chain from a ribosome. |
| Columella | |
| laminin-11 complex | A laminin complex composed of alpha5, beta2 and gamma1 polypeptide chains. |
| Phagocytic cup | An invagination of the cell membrane formed by an actin dependent process during phagocytosis. Following internalization it is converted into a phagosome. |
| SLIK (SAGA-like) complex | A SAGA-type histone acetyltransferase complex that contains Rtg2 and a smaller form of Spt7 than the fungal SAGA complex, and lacks Spt8. The complex is involved in the yeast retrograde response pathway, which is important for gene expression changes during mitochondrial dysfunction. |
| Osmiophilic body | A membrane-bounded vesicle found predominantly in Plasmodium female gametocytes, that becomes progressively more abundant as the gametocyte reaches full maturity. These vesicles lie beneath the subpellicular membrane of the gametocyte, and the release of their contents into the parasitophorous vacuole has been postulated to aid in the escape of gametocytes from the erythrocyte after ingestion by the mosquito. |
| Satellite fibril | An axoneme part that is found in the flagella of mammalian sperm and is located in the middle piece between the outer dense fibers (on the concave side of outer dense fibers as seen in cross-section). |
| CCR4-NOT core complex | The core of the CCR4-NOT complex. In Saccharomyces the CCR4-NOT core complex comprises Ccr4p, Caf1p, Caf40p, Caf130p, Not1p, Not2p, Not3p, Not4p, and Not5p. |
| Intrinsic component of peroxisomal membrane | The component of the peroxisomal membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor), which spans or is embedded in one or both leaflets of the membrane. |
| DnaA-oriC complex | |
| Cvt vesicle | A cytosolic vesicle that is enclosed by a double membrane and is implicated in the cytoplasm to vacuole targeting pathway. These vesicles are found in the yeast S. cerevisiae, and contain vacuolar hydrolases, aminopeptidase I (Ape1p) and alpha-mannosidase (Ams1p). |
| Longitudinal side of cell surface | |
| Chromaffin granule membrane | The lipid bilayer surrounding a chromaffin granule, a specialized secretory vesicle found in the cells of adrenal glands and various other organs, which is concerned with the synthesis, storage, metabolism, and secretion of epinephrine and norepinephrine. |
| trimethylamine-N-oxide reductase (cytochrome c) complex | |
| Germ tube | The slender tubular outgrowth first produced by most spores in germination. |
| AP-5 adaptor complex | An AP-type membrane coat adaptor complex that in humans consists of beta5, zeta, mu5 and sigma5 subunits and is found associated with membranes in the endosomes; it is not clear whether AP-5 forms clathrin coats in vivo. |
| Anchoring collagen complex | Any collagen complex which links one collagen assembly, such as a collagen fibril or sheet, to other structures. |
| NAGS/NAGK complex | |
| Terminal web | |
| Outer membrane protein complex | |
| Axonemal basal plate | Part of the axoneme consisting of a highly electron-dense region at the distal end of the ciliary transition zone within the axonemal lumen at which the axonemal central pair of microtubules is connected to the rest of the axonemal structure. |
| Axon hillock | Portion of the neuronal cell soma from which the axon originates. |
| SBF transcription complex | |
| ATPase inhibitor complex | |
| ATP-dependent citrate lyase complex | |
| Dentate gyrus mossy fiber | Distinctive, unmyelinated axons produced by granule cells. |
| Dendritic tuft | The terminal specialization found in some types of dendrites which consists of numerous small terminal branches, giving the dendrite a tufted appearance. |
| Collagen trimer | A protein complex consisting of three collagen chains assembled into a left-handed triple helix. These trimers typically assemble into higher order structures. |
| Spore wall | The specialized envelope lying outside the cell membrane of a spore. |
| Ciliary cap | |
| MHC class II protein complex | A transmembrane protein complex composed of an MHC class II alpha and MHC class II beta chain, and with or without a bound peptide or polysaccharide antigen. |
| ERBB3:ERBB2 complex | |
| Basal part of cell | The region of a cell situated near the base. For example, in a polarized epithelial cell, the basal surface rests on the basal lamina that separates the epithelium from other tissue. |
| Cone photoreceptor outer segment | |
| Exomer complex | A protein complex that forms a coat structure on vesicles involved in exocytosis of proteins from the trans-Golgi network to the cell surface; in Saccharomyces, the complex contains Chs5p, Chs6p, and Chs6p paralogues. |
| Nuclear pre-replicative complex | A protein-DNA complex assembled at eukaryotic DNA replication origins during late mitosis and G1, allowing the origin to become competent, or 'licensed', for replication. The complex normally includes the origin recognition complex (ORC), Cdc6, Cdt1 and the MiniChromosome Maintenance (Mcm2-7) proteins. |
| Cytostome | Stable, specialized structure for the ingestion of food by the cell into phagosomes. |
| Plastid nucleoid | The region of a plastid to which the DNA is confined. |
| IgG B cell receptor complex | An IgG immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of an IgG isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| Type V protein secretion system complex | A complex of proteins that permits the translocation of proteins across the outer membrane via a transmembrane pore, formed by a beta-barrel, into the extracellular milieu or directly into host cells; the secreted proteins contain all the information required for translocation of an effector molecule through the cell envelope. The type V secretion systems includes the autotransporters (type Va), the two-partner secretion system (type Vb) and the Oca family (type Vc). |
| Dimethyl sulfoxide reductase complex | |
| Hrd1p ubiquitin ligase complex | A multiprotein complex that recognizes and ubiquitinates proteins with misfolded luminal and membrane domains during ER-associated protein degradation (ERAD). In S. cerevisiae, this complex contains the ubiquitin ligase Hrd1p. |
| Cyclin D1-CDK6 complex | A protein complex consisting of cyclin D1 and cyclin-dependent kinase 6 (CDK6). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Asi complex | |
| Food vacuole | Vacuole within a parasite used for digestion of the host cell cytoplasm. An example of this component is found in the Apicomplexa. |
| P-TEFb-cap methyltransferase complex | |
| Neuronal ribonucleoprotein granule | A ribonucleoprotein complex that is found in the cytoplasm of axons and dendrites, and transports translationally silenced mRNAs to dendritic synapses, where they are released and translated in response to specific exogenous stimuli. |
| Ssh1 translocon complex | A translocon complex that contains a core heterotrimer of alpha, beta and gamma subunits, and may contain additional proteins (translocon-associated proteins or TRAPs); in budding yeast the core proteins are Ssh1p, Sbh2p, and Sss1p. The Ssh1 translocon complex is involved in the cotranslational pathway of protein transport across the ER membrane, and recognizes proteins bearing strongly hydrophobic signal sequences. |
| Exodeoxyribonuclease VII complex | |
| Gut granule | |
| Ecsit-NDUFAF1 complex | |
| Acidocalcisome membrane | The lipid bilayer surrounding an acidocalcisome. |
| Gemin3-Gemin4-Gemin5 complex | A protein complex that contains Gemin3 (DDX20), Gemin4, and Gemin5, and can bind to snRNAs; may be an intermediate in SMN complex assembly. |
| Leading edge of axonal growth cone | |
| Golgi trans cisterna | The Golgi cisterna farthest from the endoplasmic reticulum; the final processing compartment through which proteins pass before exiting the Golgi apparatus; the compartment in which N-linked protein glycosylation is completed. |
| Fascia adherens | A cell-cell adherens junction that contains the transmembrane protein N-cadherin, which interacts with identical molecules from neighboring cells to form a tight mechanical intercellular link; forms a large portion of the intercalated disc, the structure at which myofibrils terminate in cardiomyocytes. |
| pyrophosphate-dependent phosphofructokinase complex | Heterodimeric complex that catalyzes the pyrophosphate-dependent phosphorylation of D-fructose 6-phosphate into D-fructose 1,6-bisphosphate. |
| ERBB4-ERBB4 complex | A homodimeric complex containing two monomers of the tyrosine kinase receptor ERBB4 (also called HER4). |
| NF-kappaB p50/p65 complex | A heterodimer of NF-kappa B p50 and p65 subunits. |
| Flagellum attachment zone | |
| Heterotetrameric decaprenyl diphosphate synthase complex | |
| U12 snRNP | A ribonucleoprotein complex that contains small nuclear RNA U12. |
| Plastid ribosome | A ribosome contained within a plastid. |
| Magnesium chelatase complex | |
| Golgi cis cisterna | The Golgi cisterna closest to the endoplasmic reticulum; the first processing compartment through which proteins pass after export from the ER. |
| Spliceosomal tri-snRNP complex | A spliceosomal snRNP complex containing U4 and U6 (or U4atac and U6atac) snRNAs and U5 snRNAs and associated proteins. |
| Stereocilium membrane | The portion of the plasma membrane surrounding a stereocilium. |
| Podosome core | |
| Nucleolus organizer region | A region of a chromosome where nucleoli form during interphase, and where genes encoding the largest rRNA precursor transcript are tandemly arrayed. |
| Integrin alphaX-beta2 complex | An integrin complex that comprises one alphaX subunit and one beta2 subunit. |
| Acrosomal lumen | The volume enclosed within the acrosome membrane. |
| Synaptic vesicle, readily releasable pool | |
| FAL1-SGD1 complex | |
| AP-3 adaptor complex | A heterotetrameric AP-type membrane coat adaptor complex that consists of beta3, delta, mu3 and sigma3 subunits and is found associated with endosomal membranes. AP-3 does not appear to associate with clathrin in all organisms. In at least humans, the AP-3 complex can be heterogeneric due to the existence of multiple subunit isoforms encoded by different genes (beta3A and beta3B, mu3A and mu3B, and sigma3A and sigma3B). |
| Ectoplasm | Granule free cytoplasm, lying immediately below the plasma membrane. |
| MPP7-DLG1-LIN7 complex | A heterotrimeric protein complex formed by the association of MMP7, DLG1 and either LIN7A or LIN7C; regulates the stability and localization of DLG1 to cell junctions. |
| Polkadots | A punctate, filamentous structure composed of Bcl10 that appears in the cytoplasm of T-cells shortly after T-cell receptor stimulation. Polkadots stands for Punctate Oligomeric Killing and Activating DOmains Transducing Signals. |
| Chloroplast nucleoid | The region of a chloroplast to which the DNA is confined. |
| Annuli extracellular matrix | The extracellular matrix that is a regularly spaced circumferential ridge present in the cortical region of the cuticle. Annuli are delineated by annular furrows and are present throughout the cuticle with the exception of lateral regions where longitudinal alae are present. |
| Cortical layer of collagen and cuticulin-based cuticle extracellular matrix | The cuticle layer that lies directly beneath the lipid-containing epicuticle. The cortical layer contains collagens and insoluble, non-collagenous cuticulins and is characterized by a distinct annular pattern consisting of regularly spaced annular ridges delineated by annular furrows. An example of this component is found in Caenorhabditis elegans. |
| IRE1-TRAF2-ASK1 complex | |
| BtuCD complex | |
| Gamma DNA polymerase complex | A DNA polymerase complex consisting of a large subunit, responsible for the catalytic activities, and a small accessory subunit. Functions in the replication and repair of mitochondrial DNA. |
| Collagen and cuticulin-based cuticle extracellular matrix | A collagen and cuticulin-based noncellular, multilayered structure that is synthesized by an underlying ectodermal (hypodermal) cell layer. The cuticle serves essential functions in body morphology, locomotion, and environmental protection. An example of this component is found in Caenorhabditis elegans. |
| MPF complex | A complex consisting of a Cdc2-class (also known as Cdc28) cyclin-dependent kinase and an M-phase cyclin such as S. pombe Cdc13. The MPF complex phosphorylates and activates the anaphase promoting complex (APC). |
| nucleotide-excision repair factor 4 complex | One of several protein complexes involved in nucleotide-excision repair; possesses DNA damage recognition and DNA-dependent ATPase activities. In S. cerevisiae, it is composed of Rad7p and Rad16p. |
| Scintillon | A body present in the cytoplasm of some dinoflagellates, which is the source of bioluminescence; emits light on acidification in the presence of oxygen. |
| inaD signaling complex | A complex of proteins that are involved in phototransduction and attached to the transient receptor potential (TRP) channel. The protein connections are mediated through inaD. |
| Cyclin A2-CDK2 complex | A protein complex consisting of cyclin A2 and cyclin-dependent kinase 2 (CDK2). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Ras guanyl-nucleotide exchange factor complex | |
| Ciliary shaft | |
| Basolateral recycling endosome | |
| Lysosomal HOPS complex | |
| PDX1-PBX1b-MRG1 complex | A protein complex that contains the homeodomain proteins PDX1, PBX1b and MRG1 (MEIS2) and is involved in the transcriptional regulation of pancreatic acinar cell-specific genes. |
| Lewy body-like hyaline inclusion | Cytoplasmic inclusion found in neurons. It consists of filaments and granular materials, exhibits a dense core with a rough peripheral halo and lacks a limiting membrane. The filaments of these inclusions are composed of approximately 15-25 nm granule-coated fibrils in association with normal 10-nm neurofilaments. |
| Dendritic spine head | Distal part of the dendritic spine, that carries the post-synaptic density. |
| bacterial-type flagellum hook | The portion of the flagellum that connects the filament to the basal body. Examples of this component are found in bacteria. |
| nucleotide-excision repair, preincision complex | |
| Ric1-Rgp1 guanyl-nucleotide exchange factor complex | A protein complex that acts as a nucleotide exchange factor for the GTPase Ypt6p, and is required for fusion of endosome-derived vesicles with the Golgi. |
| Type III polyketide synthase complex | A polyketide synthase complex that consists of two identical ketosynthase polypeptides. |
| H-NS-Hha complex | |
| Capitate projection | Simple or compound process of epithelial glial cells with a spherical head that inserts into photoreceptor axons. Capitate projections have only been observed in Brachycera (flies). |
| glycerol-3-phosphate-transporting ATPase complex | |
| Cone telodendria | |
| Type II polyketide synthase complex | A polyketide synthase complex that consists of several different polypeptide chains, each of which catalyzes a single reaction. |
| Lsd1/2 complex | A nucleosome-binding protein complex that comprises two SWIRM domain histone demethylases and two PHD finger proteins. The complex is involved in transcriptional regulation via heterochromatic silencing and the regulation of chromatin boundary formation, and was first identified in fission yeast. |
| Isoamylase complex | A protein complex whose composition varies amongst species; in rice it probably exists in a homo-tetramer to homo-hexamer form and in Gram-negative bacteria as a dimer. Functions in the hydrolysis of alpha-(1,6)-D-glucosidic branch linkages. |
| CHOP-ATF3 complex | |
| Proplastid | The precursor of other plastids. |
| Dendriole | Small dendrites that makes up a brush structure found as the terminal specialization of a dendrite of a unipolar brush cell (UBC). |
| Sieve area | A pit-like area in the cell wall of a sieve element; contains pores lined with callose and occupied by strands of protoplasmic material that interconnect the protoplasts of contiguous sieve elements. |
| Integral component of Golgi membrane | The component of the Golgi membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Smooth muscle dense body | Electron-dense region associated with a smooth muscle contractile fiber. |
| Cyclin D3-CDK6 complex | A protein complex consisting of cyclin D3 and cyclin-dependent kinase 6 (CDK6). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Glial filament | An intermediate filament composed of glial fibrillary acidic protein (GFAP) and found in astrocytes. |
| Ornithine carbamoyltransferase complex | |
| vanadium-iron nitrogenase complex | |
| Leading edge of lamellipodium | |
| Stigma papilla | A plant cell papilla that is part of a stigma papilla cell. |
| Plant cell papilla | A cell projection that is a short, rounded projection from a plant epidermal cell. |
| PTW/PP1 phosphatase complex | A protein serine/threonine phosphatase complex that contains a catalytic subunit (PPP1CA, PPP1CB or PPP1CC) and the regulatory subunits PPP1R10 (PNUTS), TOX4 and WDR82, and plays a role in the control of chromatin structure and cell cycle progression during the transition from mitosis into interphase. |
| Meiotic spindle pole | |
| Sperm principal piece | The segment of the sperm flagellum where the mitochondrial sheath ends, and the outer dense fibers (ODFs) associated with outer axonemal doublets 3 and 8 are replaced by the 2 longitudinal columns of the fibrous sheath (FS) which run the length of the principal piece and are stabilized by circumferential ribs. The principal piece makes up ~2/3 of the length of the sperm flagellum and is defined by the presence of the FS and of only 7 (rather than 9) ODFs which taper and then terminate near the distal end of the principal piece. |
| Intrinsic component of Golgi membrane | The component of the Golgi membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor), which spans or is embedded in one or both leaflets of the membrane. |
| Eyespot apparatus | |
| symmetric, GABA-ergic, inhibitory synapse | |
| U4/U6 x U5 tri-snRNP complex | A ribonucleoprotein complex formed by the association of the U4/U6 and U5 small nuclear ribonucleoproteins. |
| Tubular endosome | A network of fine tubules in the vicinity of the Golgi complex and around the centriole. |
| PAS complex | A class III phosphatidylinositol 3-kinase complex that contains a phosphatidylinositol-3-phosphate 5-kinase subunit (Fab1p in yeast; PIKfyve in mammals), a kinase activator, and a phosphatase, and may also contain additional proteins; it is involved in regulating the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate. In mammals the complex is composed of PIKFYVE, FIG4 and VAC14. In yeast it is composed of Atg18p, Fig4p, Fab1p, Vac14p and Vac7p. |
| Casparian strip | Region of plant cell wall specialised to act as a seal to prevent back leakage of secreted material (analogous to tight junction between epithelial cells). Found particularly where root parenchymal cells secrete solutes into xylem vessels. The barrier is composed of suberin; a fatty substance, containing long chain fatty acids and fatty esters, also found in the cell walls of cork cells (phellem) in higher plants. |
| ERBB4-ERBB3 complex | A heterodimeric complex between the tyrosine kinase receptors ERBB4 (also called HER4) and ERBB3 (also called HER3). ERBB3 has impaired kinase activity so relies on the kinase activity of its heterodimer partner for activation and signal transmission. |
| CHOP-ATF4 complex | |
| Nucleolar preribosome | Any complex of pre-rRNAs, ribosomal proteins, and associated proteins formed in the nucleolus during ribosome biogenesis. |
| RAD6-UBR2 ubiquitin ligase complex | |
| Herring body | |
| Heterochromatin island | |
| Right nucleus | |
| Cleavage body | A nuclear body that contains proteins involved in pre-mRNA 3'-end cleavage and polyadenylation, such as DDX1, CSTF2 and CPSFs, as well as the transcription factors TFIIE and TFIIF. Cleavage bodies are localized adjacent to Cajal bodies and are involved in mRNA3'-end processing. |
| Trans spliceosomal complex | A spliceosomal complex that forms during the addition of a specific spliced leader (SL) sequence to the 5'-end of a messenger RNA primary transcript, a process which occurs in a number of eukaryotic organisms, including trypanosomatid protozoans, euglenoids, nematodes, trematodes, and chordates. |
| Platelet SNARE complex | |
| Old mitotic spindle pole body | The spindle pole body that exists in a cell prior to spindle pole body duplication. An old spindle pole body segregates to the daughter cell upon mitosis, and lacks active proteins involved in signaling exit from mitosis. |
| Perinucleolar compartment | The perinucleolar compartment (PNC) is a subnuclear structure associated with, but structurally distinct from, the nucleolus. The PNC contains large amounts of the heterogeneous nuclear ribonucleoprotein complex (hnRNP) called hnRNP 1 (PTB). Many RNA binding proteins as well as RNA polymerase III transcripts are highly enriched in this compartment. PTB and pol III transcripts are required for the integrity of the PNC. |
| Female pronucleus | The pronucleus originating from the ovum that is being fertilized. |
| Early recombination nodule | An electron dense structure that is associated with meiotic chromosomes in leptotene or zygotene during meiosis I. |
| Cytoplasmic U snRNP body | A ribonucleoprotein complex that can be visualized as a focus in the cytoplasm, and contains uridine-rich small nuclear ribonucleoproteins (U snRNPs) and essential snRNP assembly factors. These U bodies are invariably found in association with P bodies. |
| preribosome, large subunit precursor | A preribosomal complex consisting of 27SA, 27SB, and/or 7S pre-rRNA, 5S rRNA, ribosomal proteins including late-associating large subunit proteins, and associated proteins; a precursor of the eukaryotic cytoplasmic large ribosomal subunit. |
| Lateral plasma membrane | The portion of the plasma membrane at the lateral side of the cell. In epithelial cells, lateral plasma membranes are on the sides of cells which lie at the interface of adjacent cells. |
| Mating projection tip | The apex of the mating projection in unicellular fungi exposed to mating pheromone; site of polarized growth. |
| Amyloplast starch grain | |
| Dynein axonemal particle | |
| Cyclin K-CDK13 complex | A protein complex consisting of cyclin Kand cyclin-dependent kinase 13 (CDK13). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Meiotic spindle pole body | The microtubule organizing center on a spindle that forms as part of meiosis; functionally homologous to the animal cell centrosome. |
| Protein C inhibitor-thrombin complex | A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and thrombin (F2); formation of the complex inhibits the serine protease activity of thrombin. |
| CLRC complex | |
| Epidermal lamellar body | A specialized secretory organelle found in keratinocytes and involved in the formation of an impermeable, lipid-containing membrane that serves as a water barrier and is required for correct skin barrier function. |
| Immunoglobulin complex, circulating | An immunoglobulin complex that is secreted into extracellular space and found in mucosal areas or other tissues or circulating in the blood or lymph. In its canonical form, a circulating immunoglobulin complex is composed of two identical heavy chains and two identical light chains, held together by disulfide bonds. Some forms of are polymers of the basic structure and contain additional components such as J-chain and the secretory component. |
| glycine-gated chloride channel complex | A protein complex that forms a transmembrane channel through which chloride ions may pass in response to glycine binding to the channel complex or one of its constituent parts. |
| TRC complex | An ER membrane insertion complex that contains subunits that recognize two types of transmembrane domain signals. In budding yeast the complex contains Get4p, Get5p, Sgt2p, and at least two heat shock proteins (HSPs). |
| CoA-synthesizing protein complex | |
| Pyruvate kinase complex | |
| Actin cap | Polarized accumulation of cytoskeletal proteins (including F-actin) and regulatory proteins in a cell. An example of this is the actin cap found in Saccharomyces cerevisiae. |
| MAML1-RBP-Jkappa- ICN1 complex | A protein complex that consists of the intracellular domain of Notch1 (ICN1), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-1 (MAML1); the complex is involved in transcriptional activation in response to Notch-mediated signaling. |
| Tubulobulbar complex | Actin-based structures involved in establishing close contact between Sertoli-Sertoli cells or Sertoli-spermatids in the seminiferous tubules of the testes. |
| Cyclin D2-CDK4 complex | A protein complex consisting of cyclin D2 and cyclin-dependent kinase 4 (CDK4). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Thorny excrescence | Large complex spine protruding from a dendrite. Each excrescence is formed by a cluster of spine heads. |
| G-protein beta/gamma-subunit complex | The heterodimer formed by the beta and gamma subunits of a heterotrimeric G protein, which dissociates from the alpha subunit upon guanine nuclotide exchange. |
| ModE complex | |
| Alpha DNA polymerase:primase complex | A complex of four polypeptides, comprising large and small DNA polymerase alpha subunits and two primase subunits, which catalyzes the synthesis of an RNA primer on the lagging strand of replicating DNA; the smaller of the two primase subunits alone can catalyze oligoribonucleotide synthesis. |
| SREBP-SCAP-Insig complex | A protein complex formed by the association of sterol regulatory element binding protein (SREBP), SREBP-cleavage-activating protein (SCAP), and an Insig protein (Insig-1 or Insig-2) in the ER membrane. |
| Pilus shaft | The long, slender, mid section of a pilus. |
| Left anterior flagellum | |
| Hippocampal mossy fiber | |
| Ciliary basal body | A membrane-tethered, short cylindrical array of microtubules and associated proteins found at the base of a eukaryotic cilium (also called flagellum) that is similar in structure to a centriole and derives from it. The cilium basal body is the site of assembly and remodelling of the cilium and serves as a nucleation site for axoneme growth. As well as anchoring the cilium, it is thought to provide a selective gateway regulating the entry of ciliary proteins and vesicles by intraflagellar transport. |
| Spanning component of membrane | The component of a membrane consisting of gene products and protein complexes that have some part that spans both leaflets of the membrane. |
| Melanosome lumen | The volume enclosed by the melanosome membrane. |
| BAX complex | An oligomeric protein complex consisting of BAX, a member of the Bcl-2 family of anti- and proapoptotic regulators. |
| Prospore membrane | The prospore membrane is a double-membraned structure that extends from the cytoplasmic face of the spindle pole bodies to encompass the spindle pole bodies and the four nuclear lobes that are formed during meiosis. It helps isolate the meiotic nuclei from the cytoplasm during spore formation and serves as a foundation for the formation of the spore walls. An example of this component is found in Schizosaccharomyces pombe. |
| Equatorial cell cortex | |
| Extracellular core region of desmosome | |
| Mad-Max complex | A transcriptional repressor complex that consists of a heterodimer of the bHLH-ZIP proteins Mad and Max. |
| Actin wave | |
| Cul4B-RING E3 ubiquitin ligase complex | A ubiquitin ligase complex in which a cullin from the Cul4B subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by unknown subunits. |
| ascospore-type prospore | An immature spore undergoing development. The spore usually consists of nucleic acid, prospore membrane(s) that encase the nucleic acid, and ultimately a cell wall that covers the membrane(s). This type of spore is observed in ascospore-forming fungi. |
| laminin-8 complex | A laminin complex composed of alpha4, beta1 and gamma1 polypeptide chains. |
| G protein-coupled receptor homodimeric complex | |
| Inactive sex chromosome | |
| Periciliary membrane compartment | A membrane domain at the base of cilia and flagella that is enriched in endocytosis-associated proteins and vesicles and that appears to function in regulating ciliary membrane homeostasis. |
| Hydrogenosome | A spherical, membrane-bounded organelle found in some anaerobic protozoa, which participates in ATP and molecular hydrogen formation. |
| Gemin6-Gemin7-unrip complex | A protein complex that contains Gemin6, Gemin7, and unrip (STRAP), and can bind to snRNAs; may play a role in snRNP assembly. |
| Sieve plate | A part of the cell wall of a sieve tube member that bears one or more highly specialized sieve areas. |
| micropexophagy-specific membrane apparatus | A membrane-bounded flattened sac that is formed during micropexophagy between the membrane tips of an engulfing vacuole, completing the engulfment and sequestration of peroxisomes from the cytosol, and forming a micropexophagic body within the lumen of the vacuole. |
| Dense body | An electron dense body which may contain granules. |
| Plasma membrane fumarate reductase complex | |
| Nucleosomal methylation activator complex | A protein complex that contains eight subunits in common with the SWI/SNF complex, plus the ATPase BRG1 (SMARCA4) and the histone methyltransferase CARM1; the complex is involved in regulating nuclear receptor-dependent transcription. |
| Omega speckle | A nucleoplasmic speckle distributed in the interchromatin space of cells in close proximity to chromatin. Omega speckles are distinct from interchromatin granules and contain heterogeneous nuclear RNA-binding proteins (hnRNPs). |
| Methanophenazine reducing hydrogenase complex | |
| Endospore external encapsulating structure | The structures that lie outside the inner membrane and surround the entire endospore; consists of a peptidoglycan-containing inner layer (the endospore cortex) surrounded by a multilayered proteinaceous coat. An exosporium may be present as an extreme outer layer. |
| RNP body | |
| MIM complex | |
| Plasma membrane respiratory chain complex II | |
| Aleurone grain | A membrane-bounded storage granule found in cells of the aleurone layer in plants; contains either a protein matrix, protein-carbohydrate bodies and/or globoids. Aleurone grains are formed by the vacuole, rough endoplasmic reticulum and dictyosomes. |
| Muscle cell projection | A prolongation or process extending from a muscle cell. A muscle cell is a mature contractile cell, commonly known as a myocyte. This cell has as part of its cytoplasm myofibrils organized in various patterns. |
| Gas vesicle shell | The proteinaceous structure surrounding a gas vesicle. |
| DNA polymerase V complex | |
| separase-securin complex | |
| Small ribosomal subunit processing complex | |
| Mitochondrial ATP-gated potassium channel complex | |
| Fc-epsilon receptor I complex | A protein complex composed of an Fc-epsilon RI alpha chain and an Fc-epsilon RI gamma chain dimer with or without an Fc-episilon RI beta chain and additional signaling components. The complex functions primarily as an activating receptor for IgE. |
| Superoxide dismutase complex | |
| proteasome-activating nucleotidase complex | A homohexameric complex that recognizes and unfolds core proteasome substrate proteins, and translocates them to the core complex in an ATP dependent manner. |
| Nuclear inclusion body | An intranuclear focus at which aggregated proteins have been sequestered. |
| Terminal cisterna | The portion of sarcoplasmic reticulum devoted to calcium ion storage and calcium ion release. |
| MBF transcription complex | |
| UBR1-RAD6 ubiquitin ligase complex | |
| Neuronal dense core vesicle | |
| ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing | |
| Growth cone filopodium | |
| Extrinsic component of organelle membrane | The component of an organelle membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| Photosystem I antenna complex | The antenna complex of photosystem I. A photosystem has two closely linked components, an antenna containing light-absorbing pigments and a reaction center. Each antenna contains one or more light-harvesting complexes (LHCs). |
| SsuD-SsuE complex | |
| Transcription factor TFIIE complex | A transcription factor which in humans consists of a complex of two alpha and two beta chains. Recruits TFIIH to the initiation complex and helps activate both RNA polymerase II and TFIIH. |
| methanol-CoM methyltransferase complex | A heterotrimeric protein complex composed of a methanol methyltransferase subunit, a corrinoid protein and a methanol-specific corrinoid:coenzyme M methyltransferase subunit. Catalyzes the transfer of a methyl group from methanol to coenzyme M as part of the pathway of methanogenesis from methanol. |
| CRLF-CLCF1 complex | A heterodimeric protein complex that is composed of cardiotrophin-like cytokine factor 1 (product of the CLCF1 gene) and cytokine receptor-like factor 1 (product of the CRLF gene) and is secreted into the extracellular space. The CRLF-CLCF1 complex is a ligand for the ciliary neurotrophic factor (CNTF) receptor complex. |
| Varicosity | Non-terminal inflated portion of the axon, containing the specialized apparatus necessary to release neurotransmitters. |
| Intracellular immature spore | A cell or part of the cell that constitutes an early developmental stage of a spore, a small reproductive body that is highly resistant to desiccation and heat and is capable of growing into a new organism, produced especially by certain bacteria, fungi, algae, and nonflowering plants. |
| Exosporium | The outermost layer of a bacterial endospore, which is loosely attached and located outside of the endospore coat. It is generally composed of protein, carbohydrate, and perhaps lipid. |
| Cell envelope Sec protein transport complex | A transmembrane protein complex involved in the translocation of proteins across the cytoplasmic membrane. In Gram-negative bacteria, Sec-translocated proteins are subsequently secreted via the type II, IV, or V secretion systems. Sec complex components include SecA, D, E, F, G, Y and YajC. |
| 3-isopropylmalate dehydratase complex | |
| Hyaline inclusion | A glass-like, pale intracellular inclusion. |
| Integral component of external side of plasma membrane | The component of the plasma membrane consisting of the gene products that penetrate only the external side of the membrane. |
| Proteasome regulatory particle, lid subcomplex | The subcomplex of the proteasome regulatory particle that forms the peripheral lid, which is added on top of the base subcomplex. |
| Type IV site-specific deoxyribonuclease complex | |
| Dendritic microtubule | Any microtubule in a dendrite, a neuron projection. |
| RNA polymerase III transcription repressor complex | |
| nucleotide-excision repair factor 2 complex | One of several protein complexes involved in nucleotide-excision repair; possesses damaged DNA binding activity. In S. cerevisiae, it is composed of Rad4p and Rad23p. |
| Chloroplast ATP synthase complex | The protein complex that catalyzes the phosphorylation of ADP to ATP in chloroplasts. |
| MWP complex | |
| Nucleoplasmic reticulum | Long, dynamic tubular channels, formed by invagination of the nuclear envelope, that extend deep into the nucleoplasm. The channels have an underlying lamina and are implicated in functioning in signaling and transport. |
| Division septum | |
| rDNA heterochromatin | A region of heterochromatin located at the rDNA repeats in a chromosome. |
| Noc1p-Noc2p complex | A heterodimer associated with 90S and 66S preribosomes. Predominantly, but not exclusively, nucleolar; involved in ribosomal large subunit biogenesis. |
| AP-4 adaptor complex | An AP-type membrane coat adaptor complex that consists of beta4, epsilon, mu4 and sigma4 subunits and is found associated with membranes in the trans-Golgi network; it is not clear whether AP-4 forms clathrin coats in vivo. |
| Type I terminal bouton | Terminal inflated portion of the axon of a glutamatergic neuron, containing the specialized apparatus necessary to release neurotransmitters that will induce the contraction of muscle. The axon terminus is considered to be the whole region of thickening and the terminal bouton is a specialized region of it. |
| Root hair tip | The tip portion of an outgrowth of a root epidermal cell. |
| Basolateral cytoplasm | |
| COPII vesicles tethering complex | |
| Pericellular basket | Ramification of basket cell axon surrounding cell bodies, forming the characteristic pericellular baskets from which the cell class derives its name. |
| Cytosolic creatine kinase complex | A dimeric protein complex having creatine kinase activity. |
| Nuclear pore inner ring | |
| minus-end kinesin complex | Any complex that includes a dimer of molecules from the kinesin superfamily and any associated proteins, and moves towards the minus end of a microtubule. |
| PKM2 protein kinase complex | |
| U4atac snRNP | A ribonucleoprotein complex that contains small nuclear RNA U4atac. |
| Subsynaptic reticulum | An elaborate tubulolamellar membrane system that underlies the postsynaptic cell membrane. |
| Basal body patch | |
| AIP1-IRE1 complex | |
| Polar tube | A highly specialized structure unique to microsporidia that is required for host cell invasion. In the spore, the polar tube is connected at the anterior end, and then coils around the sporoplasm. Upon appropriate environmental stimulation, the polar tube rapidly discharges out of the spore, pierces a cell membrane and serves as a conduit for sporoplasm passage into the new host cell. |
| Ciliary pocket membrane | That part of the plasma membrane found in the ciliary pocket (also called flagellar pocket). |
| Nuclear pore cytoplasmic filaments | |
| Podosome ring | |
| serine-pyruvate aminotransferase complex | An enzyme complex that catalyzes the formation of hydroxypyruvate and alanine from serine and pyruvate. |
| Perinuclear endoplasmic reticulum | The portion of endoplasmic reticulum, the intracellular network of tubules and cisternae, that occurs near the nucleus. The lumen of the perinuclear endoplasmic reticulum is contiguous with the nuclear envelope lumen (also called perinuclear space), the region between the inner and outer nuclear membranes. |
| Stereocilium shaft | |
| Sid2-Mob1 complex | A protein complex that contains a protein kinase (Sid2 in S. pombe) and its regulatory subunit (Mob1). The Sid2p-Mob1p kinase complex is a component of the septation initiation network in fission yeast (called the mitotic exit network in S. cerevisiae) and is required for cytokinesis. The analogous complex in S. cerevisiae is called Dbf2p-Mob1p complex. |
| Cytosolic region | |
| ERBB4-EGFR complex | A heterodimeric complex between the tyrosine kinase receptors ERBB4 (also called HER4) and epidermal growth factor receptor (EGFR/ERBB1). |
| Sperm head plasma membrane | |
| Cell wall-bounded periplasmic space | |
| Bcl3/NF-kappaB2 complex | A protein complex containing one Bcl protein and one or more copies of NF-kappaB2; formation of complexes of different stoichiometry depends on the Bcl3:NF-kappaB2 ratio, and allow Bcl3 to exert different regulatory effects on NF-kappaB2-dependent transcription. |
| Endosomal scaffold complex | A protein complex that contains MAPKSP1 (MP1, Map2k1ip1) and ROBLD3 (p14, Mapbpip), is anchored to late endosomes, and is involved in selective activation of the ERK1 in ERK/MAPK signaling. |
| Plastid chromosome | A circular DNA molecule containing plastid encoded genes. |
| External side of cell wall | |
| DNA ligase III-XRCC1 complex | A protein complex that contains DNA ligase III and XRCC1, and is involved in base excision repair. |
| cis-Golgi network membrane | The lipid bilayer surrounding any of the compartments that make up the cis-Golgi network. |
| Postsynaptic Golgi apparatus | |
| Glycosome membrane | The lipid bilayer surrounding a glycosome. |
| Septal periplasm | The region between the plasma membrane and the cell wall, as found in organisms such as filamentous fungi. |
| ADPG pyrophosphorylase complex | |
| Accessory outer segment | |
| Mcs4 RR-MAPKKK complex | |
| ARC complex | A ribonucleoprotein complex that contains members of the Argonaute family of proteins, additional protein subunits, and duplex siRNA; required for heterochromatin assembly and siRNA generation. Possibly involved in the conversion of ds siRNA to ss siRNA. |
| Dense core granule membrane | The lipid bilayer surrounding a dense core granule. |
| Septin filament array | Arrays of septin filaments, or bars, found in a series of filamentous structures. Such structures have been observed in the prospore membrane during spore formation in S. cerevisiae and in the chlamydospore membrane during chlamydospore formation in C. albicans. |
| Transmembrane collagen trimer | Any collagen trimer that passes through a lipid bilayer membrane. |
| Porosome | A permanent cup-shaped structure at the cell plasma membrane in secretory cells. Following a secretory stimulus, secretory vesicles transiently dock and fuse at the base of porosomes and release intravesicular contents dictated by the turgor pressure generated from the swelling of secretory vesicles. |
| trimethylamine-N-oxide reductase complex | |
| Nuclear SCF ubiquitin ligase complex | A ubiquitin ligase complex, located in the nucleus, in which a cullin from the Cul1 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by a Skp1 adaptor and an F-box protein. SCF complexes are involved in targeting proteins for degradation by the proteasome. The best characterized complexes are those from yeast and mammals (with core subunits named Cdc53/Cul1, Rbx1/Hrt1/Roc1). |
| Cytochrome o ubiquinol oxidase complex | |
| Nuclear outer membrane | The outer, i.e. cytoplasm-facing, lipid bilayer of the nuclear envelope; continuous with the endoplasmic reticulum of the cell and sometimes studded with ribosomes. |
| Distal portion of axoneme | |
| Box H/ACA scaRNP complex | A box H/ACA RNP complex that is located in the Cajal body of the nucleoplasm. In higher eukaryotes, box H/ACA RNP located in Cajal bodies mediate pseudouridylation of spliceosomal snRNAs. |
| Glycine reductase complex | Complex that possesses glycine reductase activity; usually comprises three subunits, of which two are selenoproteins; the subunits are typically designated selenoprotein A, selenoprotein B and protein C. |
| Plastoglobule | A lipoprotein particle present in chloroplasts. They are rich in non-polar lipids (triglycerides, esters) as well as in prenylquinones, plastoquinone and tocopherols. Plastoglobules are often associated with thylakoid membranes, suggesting an exchange of lipids with thylakoids. |
| Lateral cell cortex | |
| imidazoleglycerol-phosphate synthase complex | |
| Nuclear meiotic cohesin complex | A cohesin complex that mediates sister chromatid cohesion in the nucleus during meiosis; has a subunit composition distinct from that of the meiotic cohesin complex. |
| Prothylakoid membrane | The membrane of prothylakoids, underdeveloped thylakoids found in etioplasts, lacking competent photosynthetic membranes. |
| Cytoplasmic side of nuclear pore | |
| Central vacuole | A membrane-enclosed sac that takes up most of the volume of a mature plant cell. Functions include storage, separation of toxic byproducts, and cell growth determination. |
| Filopodium tip | The end of a filopodium distal to the body of the cell. |
| MAD1 complex | |
| Mature chylomicron | A chylomicron that contains apolipoprotein C2 (APOC2), a cofactor for lipoprotein lipase (LPL) activity, and has a mean diameter of 500 nm and density of 0.95g/ml. Mature chylomicron particles transport exogenous (dietary) lipids from the intestines to other body tissues, via the blood and lymph. |
| U6atac snRNP | A ribonucleoprotein complex that contains small nuclear RNA U6atac. |
| Protein phosphatase type 1 complex | A protein complex that possesses magnesium-dependent protein serine/threonine phosphatase (AMD phosphatase) activity, and consists of a catalytic subunit and one or more regulatory subunits that dictates the phosphatase's substrate specificity, function, and activity. |
| Integrin alphav-beta1 complex | An integrin complex that comprises one alphav subunit and one beta1 subunit. |
| insulin-like growth factor ternary complex | A complex of three proteins, which in animals is approximately 150kDa and consists of the insulin-like growth factor (IGF), the insulin-like growth factor binding protein-3 (IGFBP-3), or -5 (IGFBP-5) and an acid-labile subunit (ALS). The complex plays a role in growth and development. |
| SC5b-7 complex | A protein complex that consist of complement components C5b6 and C7 stably inserted in a cell membrane. Formation of the SC5b-7 complex is the first phase of membrane attack complex assembly. |
| Phosphorylase kinase complex | An enzyme complex that catalyzes the phosphorylation of phosphorylase b to form phosphorylase a. |
| Encapsulin nanocompartment | |
| Peribacteroid membrane | A membrane that surrounds one or more bacteroids (such as nitrogen-fixing bacteroids within legume root nodule cells). |
| Monomeric IgA immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Axon cytoplasm | |
| organelle-enclosing lipid monolayer | A lipid monolayer that surrounds and encloses an organelle. |
| Chlorosome envelope | The structure, composed of a monolayer of glycolipids with embedded proteins, that encloses the pigments and other contents of the chlorosome. |
| Nem1-Spo7 phosphatase complex | A protein serine/threonine phosphatase complex that is involved in nuclear envelope organization, and contains proteins known in budding yeast as Nem1p and Spo7p. |
| post-lysosomal vacuole | A membrane-bounded intracellular vesicle formed late in the endocytic pathway when the pH in the vacuole becomes neutral prior to exocytosis. |
| bacteroid-containing symbiosome | A symbiosome containing any of various structurally modified bacteria, such as those occurring on the root nodules of leguminous plants. |
| bI4 intron splicing complex | |
| Chloroplast thylakoid lumen | The cavity enclosed within the chloroplast thylakoid membrane. An example of this component is found in Arabidopsis thaliana. |
| post-spliceosomal complex | A spliceosomal complex that is formed following the second splicing event and contains the spliced product, the excised intron, and three snRNPs, including U5. |
| Paraferritin complex | A cytoplasmic protein complex that contains integrin, mobilferrin and a flavin monooxygenase, is capable of reducing Fe(III) to Fe(II) utilizing NADPH, and is involved in iron transport. Fe(II) is required in the cell as the substrate for ferrochelatase in the synthesis of heme. |
| SL snRNP | A ribonucleoprotein complex that contains spliced leader (SL) RNA. |
| Mitochondrial mRNA editing complex | |
| Leaflet of membrane bilayer | |
| U12-type prespliceosome | A spliceosomal complex that is formed by the cooperative binding of the heterodimeric U11/U12 snRNP to the 5' splice site and the branch point sequence. The U12-type prespliceosome includes many proteins in addition to those found in the U11/U12 heterodimeric snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation. |
| Mitochondrial respiratory chain complex I | A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. It contains about 25 different polypeptide subunits, including NADH dehydrogenase (ubiquinone), flavin mononucleotide and several different iron-sulfur clusters containing non-heme iron. The iron undergoes oxidation-reduction between Fe(II) and Fe(III), and catalyzes proton translocation linked to the oxidation of NADH by ubiquinone. |
| Vestibular calyx terminal | |
| Anammoxosome | An intracytoplasmic membrane-bounded compartment in anaerobic ammonium oxidation (anammox) bacteria, is the site of anammox catabolism. |
| proton-transporting V-type ATPase complex | A proton-transporting two-sector ATPase complex that couples ATP hydrolysis to the transport of protons across a concentration gradient. The resulting transmembrane electrochemical potential of H+ is used to drive a variety of (i) secondary active transport systems via H+-dependent symporters and antiporters and (ii) channel-mediated transport systems. The complex comprises a membrane sector (V0) that carries out proton transport and a cytoplasmic compartment sector (V1) that catalyzes ATP hydrolysis. V-type ATPases are found in the membranes of organelles such as vacuoles, endosomes, and lysosomes, and in the plasma membrane. |
| Rhabdomere membrane | The portion of the plasma membrane surrounding the rhabdomere. |
| Pollen coat | A layer of extracellular matrix deposited onto the surface of the pollen wall upon disintegration of the tapetal layer of the anther wall in the late stages of pollen development. The composition of this material is highly heterogeneous and includes waxes, lipid droplets, small aromatic molecules, and proteins. The pollen coat is proposed to have many functions, such as holding pollen in the anther until dispersal, facilitation of pollen dispersal, protection of pollen from water loss and UV radiation, and facilitation of adhesion of pollen to the stigma. |
| Myosin IV complex | A myosin complex containing one or more class IV myosin heavy chains and associated light chains; myosin IV is relatively uncharacterized, but is predicted to have a single motor domain, one IQ motif and a tail with a Myosin Tail Homology (myTH4) domain homologous to that in the tails of myosins VII and XV. |
| Plastid thylakoid lumen | The volume enclosed by a plastid thylakoid membrane. |
| laminin-15 complex | |
| New growing cell tip | A cell tip that was newly formed at the last cell division, and that has started to grow after the cell has activated bipolar cell growth (i.e. in which new end take-off, NETO, has taken place). New end take-off is when monopolar cells initiate bipolar growth. |
| Kainate selective glutamate receptor complex | An assembly of four or five subunits which form a structure with an extracellular N-terminus and a large loop that together form the ligand binding domain. The C-terminus is intracellular. The ionotropic glutamate receptor complex itself acts as a ligand gated ion channel; on binding glutamate, charged ions pass through a channel in the center of the receptor complex. Kainate receptors are multimeric assemblies of GluR5-7 and KA-1/2 subunits. |
| Granular vesicle | A cytoplasmic membrane-bounded vesicle of varying size, but usually larger than 45 nm, with an electron dense granular core, found in noradrenergic and peptidergic cells. |
| U2-type precatalytic spliceosome | |
| Secretory dimeric IgA immunoglobulin complex | A dimeric form of secretory IgA immunoglobulin complex. |
| Chloroplast vesicle | |
| G protein-coupled receptor heterodimeric complex | |
| Caveola neck | |
| Dsc E3 ubiquitin ligase complex | An E3 ubiquitin ligase complex localized to the ER and Golgi membrane. In fission yeast comprises Dsc1, 2, 3 and 4. Involved in the processes of fission yeast sre1 (human SREBP) transcriptional activator proteolytic cleavage, the multivesicular body (MVB) pathway, and a post-endoplasmic reticulum pathway for protein catabolism. |
| alpha3-beta1 integrin-basigin complex | A protein complex that consists of an alpha3-beta1 integrin complex bound to the cell surface protein basigin. |
| Mating projection base | |
| DnaB-DnaC complex | |
| Intercellular canaliculus | An extremely narrow tubular channel located between adjacent cells. An instance of this is the secretory canaliculi occurring between adjacent parietal cells in the gastric mucosa of vertebrates. |
| Endonuclear canal | A membrane-bound structure present in the nucleus of a spermatozoon. There is variation in the number of endonuclear canals between sperm of different organisms, and some species lack these structures altogether. The endonuclear canal may provide a supporting role for the sperm nucleus, and originates during spermiogenesis from an invagination of the nuclear envelope. |
| Pi Mi complex | |
| Phosphatidylinositol 3-kinase complex, class III, type I | A class III phosphatidylinositol 3-kinase complex that is involved in autophagy. In budding yeast, this complex consists of Vps30p, Vps34p, Apg14p and Vps15p. |
| Ascospore wall | The specialized cell wall of the ascospore (spore), which is the product of meiotic division. Examples of this component are found in Fungi. |
| Chloroplast ribosome | A ribosome contained within a chloroplast. |
| Sperm midpiece | The highly organized segment of the sperm flagellum which begins at the connecting piece and is characterized by the presence of 9 outer dense fibers (ODFs) that lie outside each of the 9 outer axonemal microtubule doublets and by a sheath of mitochondria that encloses the ODFs and the axoneme; the midpiece terminates about one-fourth of the way down the sperm flagellum at the annulus, which marks the beginning of the principal piece. |
| Intrinsic component of nuclear outer membrane | The component of the nuclear outer membrane consisting of the gene products that have some covalently attached part (e.g. peptide sequence or GPI anchor) which spans or is embedded in one or both leaflets of the membrane. |
| yeast-form cell wall | |
| Bacterial pre-replicative complex | |
| Myelin sheath adaxonal region | The region of the myelin sheath nearest to the axon. |
| Cyclin B2-CDK1 complex | A protein complex consisting of cyclin B2 and cyclin-dependent kinase 1 (CDK1). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| DNA methyltransferase complex | |
| External side of cell outer membrane | The side of the outer membrane that is opposite to the side that faces the periplasm of the cell. |
| Hemidesmosome associated protein complex | Any protein complex that is part of or has some part in a hemidesmosome. |
| Flagella connector | |
| Early endosome membrane | The lipid bilayer surrounding an early endosome. |
| Multimeric ribonuclease P complex | A ribonuclease P complex that generally contains a single RNA molecule and several protein molecules. Examples of this complex are found in Archaeal species. |
| Neuron projection cytoplasm | |
| 2-iminoacetate synthase complex | |
| Prothylakoid | Underdeveloped thylakoids found in etioplasts, lacking competent photosynthetic membranes. Rapidly develop into mature thylakoids in the presence of light. |
| Cytoplasmic SCF ubiquitin ligase complex | A ubiquitin ligase complex, located in the cytoplasm, in which a cullin from the Cul1 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by a Skp1 adaptor and an F-box protein. SCF complexes are involved in targeting proteins for degradation by the proteasome. The best characterized complexes are those from yeast and mammals (with core subunits named Cdc53/Cul1, Rbx1/Hrt1/Roc1). |
| Glutamatergic postsynaptic density | |
| Pexophagosome | |
| Chromatin lock complex | |
| Hechtian strand | |
| Spindle envelope | An organelle envelope that surrounds the chromosomes and the central part of the spindle apparatus during mitosis and meiosis; observed in many invertebrates. The spindle envelope consists of membrane layers, called parafusorial membranes, derived from endoplasmic reticulum membrane; in male meiosis it forms during prometaphase and persists until early in the ensuing interphase. |
| Cone matrix sheath | |
| nucleotide-excision repair factor 3 complex | One of several protein complexes involved in nucleotide-excision repair; possesses endodeoxynuclease and DNA helicase activities. In S. cerevisiae, it is composed of Rad2p and the core TFIIH-Ssl2p complex (core TFIIH is composed of Rad3p, Tfb1p, Tfb2p, Ssl1p, Tfb4p and Tfb5p. Note that Ssl2p is also called Rad25p). |
| Fertilization envelope | A structure that lies outside the plasma membrane and surrounds the egg. The fertilization envelope forms from the vitelline membrane after fertilization as a result of cortical granule release. |
| Hyphal cell wall | The cell wall surrounding a fungal hypha. |
| Lid2 complex | |
| Enterobactin synthetase complex | A multienzyme complex usually composed of four proteins, EntB, EntD, EntE and EntF. Plays a role in the enterobactin biosynthesis pathway. |
| Proteasome core complex, beta-subunit complex | |
| telomere-telomerase complex | A complex of DNA and protein located at the end of a linear chromosome that enables replication of the telomeric repeat sequences at the end of a linear chromosome. |
| Host cellular component | |
| Stereocilium tip | |
| fungal-type cell wall | A rigid yet dynamic structure surrounding the plasma membrane that affords protection from stresses and contributes to cell morphogenesis, consisting of extensively cross-linked glycoproteins and carbohydrates. The glycoproteins may be modified with N- or O-linked carbohydrates, or glycosylphosphatidylinositol (GPI) anchors; the polysaccharides are primarily branched glucans, including beta-linked and alpha-linked glucans, and may also include chitin and other carbohydrate polymers, but not cellulose or pectin. Enzymes involved in cell wall biosynthesis are also found in the cell wall. Note that some forms of fungi develop a capsule outside of the cell wall under certain circumstances; this is considered a separate structure. |
| Plasma membrane proton-transporting ATP synthase complex | |
| Myosin XI complex | A myosin complex containing a dimer of class XI myosin heavy chains and associated light chains. Myosin XI heavy chain sizes are similar in molecular structure to the class V myosins with 5 to 6 IQ motifs and tail regions with predicted coiled coil domains (forming dimeric molecules) and large C-terminal regions. |
| Integral component of mycolate outer membrane | |
| Intrinsic component of mycolate outer membrane | |
| Sarcosine oxidase complex | |
| Outer dense plaque of desmosome | |
| Multiple synapse bouton, contacting single dendrite | |
| Cell body fiber | A neuron projection that is found in unipolar neurons and corresponds to the region between the cell body and the point at which the single projection branches. |
| Hedgehog signaling complex | A multiprotein complex that binds microtubules in a Hedgehog-dependent manner, and is required for signal transduction by members of the Hedgehog family of proteins. The core components of the complex are the serine/threonine protein kinase Fused, the kinesin motor protein Costal2 (Cos2), and a zinc finger transcription factor (Gli family members in humans, and Cubitus interruptus (Ci) in Drosophila). |
| Magnetosome | |
| Basal tubulobulbar complex | |
| Dinoflagellate sulcus | A cell surface furrow that occurs on the ventral side of a dinoflagellate cell. It partially houses the longitudinal flagellum. The sulcus intersects with the cingulum on the ventral side of a dinoflagellate cell. |
| Doa10p ubiquitin ligase complex | A multiprotein complex that recognizes and ubiquitinates membrane proteins with misfolded cytosolic domains during ER-associated protein degradation (ERAD). In S. cerevisiae, this complex contains the ubiquitin ligase Ssm4p/Doa10p. |
| Autolysosome membrane | |
| Static microtubule bundle | |
| Kelch-containing formin regulatory complex | |
| inhibin-betaglycan-ActRII complex | A protein complex that consists of inhibin, type III transforming growth factor beta receptor (also known as betaglycan), and the type II activin receptor ActRII. The complex is thought to negatively regulate the activity of activin B. |
| Growth cone membrane | The portion of the plasma membrane surrounding a growth cone. |
| Contractile vacuole | A specialized vacuole of eukaryotic cells, especially Protozoa, that fills with water from the cytoplasm and then discharges this externally by the opening of contractile vacuole pores. Its function is probably osmoregulatory. |
| Ventral disc overlap zone | |
| Postsynaptic endocytic zone | |
| CAK-ERCC2 complex | A protein complex formed by the association of the cyclin-dependent protein kinase activating kinase (CAK) holoenzyme complex with ERCC2. |
| Merozoite dense granule | Electron-dense organelle with a granular internal matrix found throughout the merozoite life cycle stage of apicomplexan parasites; contains proteins destined to be secreted into the parasitophorous vacuole following parasite invasion of a host cell. |
| Goblet cell theca | |
| beta-galactosidase complex | A protein complex that possesses beta-galactosidase activity, i.e. catalyzes the hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides. In E. coli, the complex is a homotetramer; dimeric and hexameric beta-galactosidase complexes have been observed in other species. |
| Male germline ring canal | |
| Nuclear pore transmembrane ring | |
| Inner dense plaque of desmosome | |
| COPI-coated Golgi to ER transport vesicle | |
| DNA replication factor C core complex | A protein complex containing three of the five subunits of eukaryotic replication factor C, those corresponding to human p40, p38, and p37. |
| Secondary cell wall cellulose synthase complex | A large, multimeric protein complex which catalyzes the biosynthesis of cellulose for the plant secondary cell wall. In Arabidopsis, contains the essential component proteins CESA8, CESA7, and CESA4. |
| Growth cone leading edge | |
| Ycf2/FtsHi complex | |
| Sarcoplasmic reticulum lumen | The volume enclosed by the membranes of the sarcoplasmic reticulum. |
| ferredoxin-thioredoxin reductase complex | |
| Platelet dense tubular network | A network of membrane-bounded compartments found in blood platelets, where they regulate platelet activation by sequestering or releasing calcium. The dense tubular network exists as thin elongated membranes in resting platelets, and undergoes a major ultrastructural change, to a rounded vesicular form, upon addition of thrombin. |
| Type I protein secretion system complex | |
| Noc2p-Noc3p complex | |
| Dinoflagellate hypocone | |
| Synaptobrevin 2-SNAP-25-syntaxin-1a-complexin I complex | A SNARE complex that contains synaptobrevin 2 (VAMP2), SNAP-25, syntaxin 1a, and complexin I (or orthologs thereof). |
| Pyrenoid | |
| Basolateral part of cell | |
| HICS complex | A multisubunit complex involved in cytokinesis. In the yeast Saccharomyces cerevisiae this complex consists of Sho1p, Hof1p, Inn1p and Cyk3p proteins. |
| Growth cone lamellipodium | |
| 3-phenylpropionate dioxygenase complex | Enzyme complex consisting of four proteins: the two subunits of the hydroxylase component (hcaE and hcaF), a ferredoxin (hcaC) and a ferredoxin reductase (hcaD). Converts 3-phenylpropionic acid (PP) into cis-3-(3-carboxyethyl)-3,5-cyclohexadiene-1,2-diol (PP-dihydrodiol). |
| Cytosolic pyruvate dehydrogenase complex | |
| Neurosecretory vesicle | A large cytoplasmic membrane-bounded vesicle with an electron dense granular core, up to 150-200 nm in diameter, found in neurosecretory cells in the hypothalamus. |
| Early endosome lumen | The volume enclosed by the membrane of an early endosome. |
| Middle lamella | Layer of intercellular material, chiefly pectic substances, cementing together the primary walls of contiguous cells. |
| histamine-gated chloride channel complex | |
| mannosyl-oligosaccharide 1,2-alpha-mannosidase complex | |
| PCNA-p21 complex | A protein complex that contains the cyclin-dependent protein kinase inhibitor p21WAF1/CIP1 bound to PCNA; formation of the complex inhibits DNA replication. |
| SCF-Das1 ubiquitin ligase complex | |
| Posterior cell cortex | |
| PKM2 pyruvate kinase complex | |
| Subtelomeric heterochromatin | |
| proton-transporting ATP synthase, stator stalk | |
| Mitochondrial proton-transporting ATP synthase, stator stalk | |
| Photoreceptor outer segment membrane | The membrane surrounding the outer segment of a vertebrate photoreceptor. |
| Platelet glycocalyx | |
| Macropinocytic cup | A cell projection that forms at the site of macropinocytosis, a form of endocytosis that results in the uptake of relatively large amounts of extracellular fluid. The macropinocytic cup membrane selectively excludes certain proteins, such as H36 or PM4C4 in Dictyostelium, and the underlying cytoskeleton is enriched in F-actin and coronin. |
| dolichyl-phosphate-mannose-protein mannosyltransferase Pmt1p-Pmt2p dimer complex | |
| non-growing cell tip | A cell tip at which no growth takes place. For example, in fission yeast the cell end newly formed by cell division does not grow immediately upon its formation, and lacks actin cytoskeletal structures. |
| Lateral shield | |
| Extracellular matrix of synaptic cleft | |
| Dimeric IgA immunoglobulin complex | A protein complex composed of two monomeric IgA immunoglobulin complexes linked through both direct disulfide bonds and through a disulfide binded monomer of J chain acting as a bridge. Each IgA monomer consists of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds. Dimeric IgA is sometimes complexed additionally with secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Lumenal side of endoplasmic reticulum membrane | |
| Mitochondrial respiratory chain complex IV | A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. Contains the 13 polypeptide subunits of cytochrome c oxidase, including cytochrome a and cytochrome a3. Catalyzes the oxidation of reduced cytochrome c by dioxygen (O2). |
| Etioplast envelope | The double lipid bilayer enclosing the etioplast and separating its contents from the rest of the cytoplasm; includes the intermembrane space. |
| Etioplast membrane | Either of the lipid bilayers that surround a etioplast and form the etioplast envelope. |
| Postsynaptic cytoskeleton | |
| glutamate-tRNA ligase complex | |
| 1,3-beta-D-glucan synthase complex | A protein complex that catalyzes the transfer of a glucose group from UDP-glucose to a (1->3)-beta-D-glucan chain. |
| Skeletal muscle myofibril | |
| TACC/TOG complex | A protein complex that contains the transforming acidic coiled coil (TACC) protein and the TOG protein (Mia1p/Alp7p and Alp14, respectively, in fission yeast), and is involved in microtubule array remodeling as cells progress through the cell cycle. The TACC/TOG complex is conserved in eukaryotes, associates with microtubules, and shuttles between the nucleus and the cytoplasm during interphase. |
| Endospore cortex | A layer surrounding a bacterial endospore found inside the outer endospore membrane, but outside the membrane surrounding the endospore core. It consists of peptidoglycan of a different chemical nature than that found in vegetative cell walls which results in less cross-linking of peptidoglycan. |
| BIM-BCL-2 complex | A heterodimeric protein complex consisting of BIM and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators. |
| Pleated septate junction | A septate junction in which regular arrays of electron-dense septae span the intermembrane space. |
| Caveola bulb | |
| Germline ring canal | Germline specific intercellular bridge. During cyst formation in insects, ring canals interconnect the cells of the cyst, facilitating the passage of cytoplasmic components between cells. |
| CoB-CoM heterodisulfide reductase complex | |
| Protein tyrosine phosphatase complex | |
| Septin cap | A faint structure formed of septins found at the leading edge of growth in germ tubes and hyphae in fungal cells growing filamentously. This cap of septins colocalizes with a region of the plasma membrane that is rich in ergosterol. |
| Cytoplasmic side of endosome membrane | The side (leaflet) of the endosome membrane that faces the cytoplasm. |
| Vesicle lumen | The volume enclosed by the membrane or protein that forms a vesicle. |
| Zona pellucida receptor complex | A multisubunit complex comprising the chaperonin-containing T-complex and several other components involved in mediating sperm-oocyte Interaction. |
| Tripartite ATP-independent periplasmic transporter complex | A complex consisting of two membrane proteins and one extracytoplasmic solute receptor. Such transporters transport a variety of substrates without direct ATP power, instead using energy from ion gradients. |
| Banded collagen fibril | |
| Piccolo NuA4 histone acetyltransferase complex | A heterotrimeric H4/H2A histone acetyltransferase complex with a substrate preference of chromatin over free histones. It contains a subset of the proteins found in the larger NuA4 histone acetyltransferase complex; for example, the S. cerevisiae complex contains Esa1p, Yng2p, and Epl1p. |
| Photoreceptor inner segment membrane | The membrane surrounding the outer segment of a vertebrate photoreceptor. The photoreceptor inner segment contains mitochondria, ribosomes and membranes where opsin molecules are assembled and passed to be part of the outer segment discs. |
| Cytoplasmic periphery of the nuclear pore complex | |
| Yolk | The cytoplasmic part that serves as a nutrient reserve or energy source for the developing embryo. |
| CRD-mediated mRNA stability complex | A protein complex that binds to, and promotes stabilization of, mRNA molecules containing the coding region instability determinant (CRD). In human, IGF2BP1 and at least four additional proteins: HNRNPU, SYNCRIP, YBX1, and DHX9. |
| fungal-type vacuole | |
| Podocyte primary projection | |
| Magnetosome membrane | |
| Photosystem I reaction center | A photochemical system containing P700, the chlorophyll a dimer that functions as a primary electron donor. Functioning as a light-dependent plastocyanin-ferredoxin oxidoreductase, it transfers electrons from plastocyanin to ferredoxin. |
| Riboflavin synthase complex | |
| SAS acetyltransferase complex | A protein complex that possesses histone acetyltransferase activity and links histone acetylation to the assembly of transcriptionally silent chromatin. In vitro, the complex acetylates lysine 16 of histone H4 and lysine 14 of histone H3, although the latter may not be relevant in vivo. The complex contains a catalytic subunit and at least two other subunits; in Saccharomyces, the catalytic subunit is Sas2p and additional subunits are Sas4p and Sas5p. |
| chitin-based extracellular matrix | |
| Reelin complex | |
| Yolk granule | Discrete structures that partition the water-insoluble portion of the yolk of oocytes and ova, which may or may not be membrane enclosed. |
| Endoplasmic reticulum-endosome membrane contact site | |
| Left caudal flagellum | |
| Meiotic actomyosin contractile ring | |
| nucleotide-excision repair factor 1 complex | One of several protein complexes involved in nucleotide-excision repair; possesses DNA damage recognition and endodeoxynuclease activities. In S. cerevisiae, it is composed of Rad1p, Rad10p, and Rad14p; in human the subunits are ERCC4/XPF, ERCC1 and XPA, respectively. |
| Lysosomal proton-transporting V-type ATPase complex | |
| Anterior cell cortex | |
| Superoxide dismutase copper chaperone complex | |
| Chloroplast starch grain | Plant storage body for amylose and amylopectin, 1-100um in diameter, and located in chloroplasts. Also contains small amounts of enzymes, amino acids, lipids and nucleic acids. The shape of the grain varies widely amongst species, but is often spherical or disk-shaped. |
| acetylcholine-gated channel complex | A homo- or hetero-pentameric protein complex that forms a transmembrane channel through which ions may pass in response to acetylcholine binding. |
| Spongiome | |
| Alkyl hydroperoxide reductase complex | |
| Female germline ring canal | An intercellular bridge that connects the germline cells of a female cyst. |
| Lumenal side of membrane | |
| Outer endospore membrane | The outer membrane around a bacterial endospore, located between the endospore cortex and endospore coat. |
| Pseudopodium membrane | The portion of the plasma membrane surrounding a pseudopodium. |
| Presynaptic active zone membrane | The membrane portion of the presynaptic active zone; it is the site where docking and fusion of synaptic vesicles occurs for the release of neurotransmitters. |
| Presynaptic endocytic zone | |
| Nuclear stress granule | A dense aggregation in the nucleus composed of proteins and RNAs that appear when the cell is under stress. |
| Integral component of cell outer membrane | The component of the cell outer membrane consisting of the gene products that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Cdc50p-Drs2p complex | |
| Postsynaptic specialization of symmetric synapse | |
| Mitochondrial inner membrane assembly complex | |
| U2-type prespliceosome | A spliceosomal complex that is formed by association of the 5' splice site with the U1 snRNP, while the branch point sequence is recognized by the U2 snRNP. The prespliceosome includes many proteins in addition to those found in the U1 and U2 snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation. |
| Ventral disc microtubule array | |
| Micropyle | An external encapsulating structure part of the chorion. A single cone-shaped specialization that forms an opening in the chorion that allows sperm entry into the egg prior to fertilization. |
| Puncta adhaerentia | A small version of the zonula adherens type junction, characterized by a symmetrical adherent point between two cells. |
| Peripheral region of growth cone | |
| Nuclear DNA replication factor C complex | |
| NuA3b histone acetyltransferase complex | |
| Pericanalicular vesicle | A membrane-bounded vesicle found near the apical, or pericanalicular, membrane of a hepatocyte; contains proteins involved in bile salt transport and other fluid and solute transport processes. |
| Tea1 cell-end complex | A high molecular weight complex characterized in S. pombe containing the cell-end anchoring protein Tea1. This complex is transported to the cell ends by microtubules and is involved in bipolar growth and the maintennce of normal cell polarity. |
| Hemicellulose network | |
| Nucleolar ring | |
| Ku-DNA ligase complex | |
| Acidocalcisome lumen | |
| Smooth muscle contractile fiber | The contractile fiber of smooth muscle cells. |
| Pterinosome | A tissue-specific, membrane-bounded cytoplasmic organelle within which pteridine pigments are synthesized and stored. Pterinosomes are synthesized in xanthophores and erythrophore cells and are yellow, orange or red in appearance. |
| Hrd1p ubiquitin ligase ERAD-L complex | |
| Excinuclease repair complex | Any of the protein complexes formed by the UvrABC excinuclease system, which carries out nucleotide excision repair. Three different complexes are formed by the 3 proteins as they proceed through the excision repair process. First a complex consisting of two A subunits and two B subunits bind DNA and unwind it around the damaged site. Then, the A subunits disassociate leaving behind a stable complex between B subunits and DNA. Now, subunit C binds to this B+DNA complex and causes subunit B to nick the DNA on one side of the complex while subunit C nicks the DNA on the other side of the complex. DNA polymerase I and DNA ligase can then repair the resulting gap. |
| Mitotic spindle microtubule | |
| Anaerobic ribonucleoside-triphosphate reductase complex | |
| Vacuolar proton-transporting V-type ATPase, V0 domain | The V0 domain of a proton-transporting V-type ATPase found in the vacuolar membrane. |
| proton-transporting V-type ATPase, V1 domain | A protein complex that forms part of a proton-transporting V-type ATPase and catalyzes ATP hydrolysis. The V1 complex consists of: (1) a globular headpiece with three alternating copies of subunits A and B that form a ring, (2) a central rotational stalk composed of single copies of subunits D and F, and (3) a peripheral stalk made of subunits C, E, G and H. Subunits A and B mediate the hydrolysis of ATP at three reaction sites associated with subunit A. |
| Adhesive extracellular matrix | |
| Synaptic vesicle, recycling pool | |
| Grb2-EGFR complex | A protein complex that contains the epidermal growth factor receptor (EGFR) and Grb2, and is involved in linking EGFR activation to the p21-Ras pathway. |
| Cyclin A2-CDK1 complex | A protein complex consisting of cyclin A2 and cyclin-dependent kinase 1 (CDK1). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Platelet dense granule membrane | The lipid bilayer surrounding the platelet dense granule. |
| Golgi medial cisterna membrane | |
| Intrinsic component of Golgi medial cisterna membrane | |
| Integral component of Golgi medial cisterna membrane | |
| Protein aggregate center | |
| Grb2-Shc complex | A protein complex that contains Grb2 and the adaptor protein Shc, and is involved in linking epidermal growth factor receptor (EGFR) activation to the p21-Ras pathway. |
| Ventral surface of cell | |
| Preprophase band | A dense band of microtubules, 1-3 pm wide, that appears just beneath the cell membrane before the start of cell division in the cells of higher plants. It precedes the onset of prophase and then disappears as mitosis begins, yet it somehow determines the plane of orientation of the new cell plate forming in late telophase and marks the zone of the parental cell wall where fusion with the growing cell plate ultimately occurs. |
| nucleolus-like body | |
| Sperm cytoplasmic droplet | A small amount of cytoplasm surrounded by a cell membrane that is generally retained in spermatozoa after spermiogenesis, when the majority of the cytoplasm is phagocytosed by Sertoli cells to produce residual bodies. Initially, the droplet is located at the neck just behind the head of an elongated spermatid. During epididymal transit, the cytoplasmic droplet migrates caudally to the annulus at the end of the midpiece; the exact position and time varies by species. The cytoplasmic droplet consists of lipids, lipoproteins, RNAs, a variety of hydrolytic enzymes, receptors, ion channels, and Golgi-derived vesicles. The droplet may be involved in regulatory volume loss (RVD) at ejaculation, and in most species, though not in humans, the cytoplasmic droplet is lost at ejaculation. Note that the cytoplasmic droplet is distinct from excessive residual cytoplasm that sometimes remains in epididymal spermatozoa, particularly when spermiogenesis has been disrupted. |
| Striated muscle myosin thick filament | Bipolar filaments formed of polymers of a muscle-specific myosin II isoform, found in the middle of sarcomeres in myofibrils. |
| pICln-Sm protein complex | A protein complex that contains pICln (CLNS1A) and several Sm proteins, including SmD1, SmD2, SmE, SmF, and SmG. |
| Schaffer axon collateral | |
| Contractile vacuole pore | Stable structure that regulates the flow of liquid between the contractile vacuole and the surrounding medium. |
| Recycling endosome membrane | The lipid bilayer surrounding a recycling endosome. |
| Sulfopyruvate decarboxylase complex | |
| H-gal-GP complex | |
| piccolo-bassoon transport vesicle | |
| Contractile vacuole complex | |
| Egg chorion | |
| Nuclear exosome (RNase complex) | Complex of 3'-5' exoribonucleases found in the nucleus. |
| Cdc24p-Far1p-Gbetagamma complex | |
| Eukaryotic 43S preinitiation complex | A protein complex composed of the 40S ribosomal subunit plus eIF1A, eIF3, and eIF2-GTP-bound methionyl-initiator methionine tRNA. |
| Cytoplasmic vesicle lumen | |
| Golgi cisterna membrane | The lipid bilayer surrounding any of the thin, flattened compartments that form the central portion of the Golgi complex. |
| Mitochondrial inner boundary membrane | |
| Sensory dendrite | A dendrite that is found on a sensory neuron, and directly transduces a sensory signal from the sensory neuron to another neuron. |
| Cyanelle thylakoid membrane | |
| Cyanelle thylakoid | |
| Microsporocyte nucleus | The nucleus of the microsporocyte. The microsporocyte is a diploid cell in which meiosis will occur, resulting in four microspores. A microspore is a spore that, in vascular plants, gives rise to a male gametophyte. |
| Chromoplast membrane | Either of the lipid bilayers that surround a chromoplast and form the chromoplast envelope. |
| Chromoplast envelope | The double lipid bilayer enclosing the chromoplast and separating its contents from the rest of the cytoplasm; includes the intermembrane space. |
| Fibrillar collagen trimer | Any triple helical collagen trimer that forms fibrils. |
| Extrinsic component of endoplasmic reticulum membrane | The component of the endoplasmic reticulum membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| Nuclear exosome focus | |
| Transcription factor TFIIIC2 complex | |
| Mei2 nuclear dot complex | |
| Presynaptic grid | A hexagonal array of electron dense particles attached to the cytoplasmic face of the presynaptic membrane. |
| Reservosome | |
| Nucleolar ribonuclease P complex | A ribonuclease P complex located in the nucleolus of a eukaryotic cell, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. Eukaryotic nucleolar ribonuclease P complexes generally contain a single RNA molecule that is necessary but not sufficient for catalysis, and several protein molecules. |
| IgA B cell receptor complex | An IgA immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins. |
| Stereocilium base | |
| Left tetrad | |
| ATP-binding cassette (ABC) transporter complex, transmembrane substrate-binding subunit-containing | A complex for the transport of metabolites into the cell, consisting of 4 subunits: a transmembrane substrate-binding protein (known as the S component), and an energy-coupling module that comprises two ATP-binding proteins (known as the A and A' components) and a transmembrane protein (known as the T component). Transport of the substrate across the membrane is driven by the hydrolysis of ATP. |
| Right tetrad | |
| Perikaryon | The portion of the cell soma (cell body) that excludes the nucleus. |
| Rod photoreceptor disc lumen | |
| glucose-1-phosphate adenylyltransferase complex | |
| Periplasmic flagellum | Flagellar filaments located in the periplasmic space; characterized in spirochetes, in which they are essential for shape and motility. Composed of a core surrounded by two sheath layers, the flagella rotate to allow migration of the cell through viscous media, which would not be possible using external flagella. |
| alphaE-beta7 integrin-E-cadherin complex | A protein complex that consists of an alphaE-beta7 integrin complex bound to E-cadherin. |
| RSP5-BUL ubiquitin ligase complex | |
| Myosin XVIII complex | A myosin complex containing a class XVIII myosin heavy chain and associated light chains; myosin XVIII heavy chains contain an N-terminal PDZ domain. |
| Eisosome filament | |
| TRAF2-GSTP1 complex | A protein complex comprising tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and glutathione S-transferase pi 1 (GSTP1). This complex is thought to disrupt the TNF signaling cascade, thus down-regulating inflammatory responses. |
| Endolysosome lumen | The volume enclosed by the membrane of an endolysosome. An endolysosome is a transient hybrid organelle formed by fusion of a late endosome with a lysosome. |
| Cyanosome | |
| Transforming growth factor beta ligand-receptor complex | |
| iNOS-S100A8/A9 complex | |
| Cerebellar granule cell to Purkinje cell synapse | |
| Nematocyst | An organelle found in cnidoblast (nematoblast) cells. When matured, these stinging organelles store toxins and can deliver them when the cnidocil (a short extension of the cnidocyst) is stimulated by a prey or another stimulus. |
| Transcription factor TFIIIB-beta complex | |
| procollagen-proline 4-dioxygenase complex | A protein complex that catalyzes the formation of procollagen trans-4-hydroxy-L-proline and succinate from procollagen L-proline and 2-oxoglutarate, requiring Fe2+ and ascorbate. Contains two alpha subunits that contribute to most parts of the catalytic sites, and two beta subunits that are identical to protein-disulfide isomerase. |
| Gtr1-Gtr2 GTPase complex | A heterodimer GTPase complex. In S. cerevisiae, this complex contains Gtr1p and Gtr2p proteins. |
| Macrophage migration inhibitory factor receptor complex | A protein complex that binds macrophage migration inhibitory factor. Comprises CD74 and CD44 cell surface proteins. |
| Polar microtubule | Any of the spindle microtubules that come from each pole and overlap at the spindle midzone. This interdigitating structure consisting of antiparallel microtubules is responsible for pushing the poles of the spindle apart. |
| Rod photoreceptor disc membrane | |
| Collagen type XI trimer | A collagen heterotrimer containing type XI alpha chains in alpha1(XI)alpha2(XI)alpha3(XI) trimers; type XI collagen triple helices associate to form fibrils. |
| Nucleomorph | A small, vestigial nucleus found in some plastids that derive from a eukaryotic endosymbiont. Observed in chlorarachniophytes and cryptomonads, which acquired their plastids from a green and red alga respectively. |
| alpha-heterochromatin | |
| Lysosomal glycocalyx | The polysaccharide-based coating on the inner side of a lysosomal membrane that protects it from digestion by lysosomal enzymes. |
| fatty-acyl-CoA synthase complex | |
| Centrosomal corona | An amorphous structure surrounding the core of the centrosome, from which microtubules are nucleated; contains gamma-tubulin. |
| Endoplasmic reticulum-Golgi intermediate compartment membrane | The lipid bilayer surrounding any of the compartments of the endoplasmic reticulum (ER)-Golgi intermediate compartment system. |
| BIM-BCL-xl complex | A heterodimeric protein complex consisting of BIM and BCL-xl, members of the Bcl-2 family of anti- and proapoptotic regulators. |
| Mitochondrial oxoglutarate dehydrogenase complex | |
| TERT-RMRP complex | A ribonucleoprotein complex that has RNA-directed RNA polymerase (RdRP) activity, and is composed of telomerase reverse transcriptase (TERT) and the non-coding RNA component of mitochondrial RNA processing endoribonuclease (RMRP). |
| Meiotic septin complex | |
| Magnetosome lumen | |
| Mitochondrial derivative | The major and minor mitochondrial derivatives are the mitochondria of the sperm tail and derive by the unfolding of the Nebenkern during flagellum elongation. |
| Perforation plate | |
| Secretory granule lumen | The volume enclosed by the membrane of a secretory granule. |
| Omegasome membrane | |
| Central cylinder | |
| Inhibitory neuromuscular junction | |
| senescence-associated vacuole | |
| Nebenkern | A product of the fusion of the mitochondria during spermatogenesis. After the completion of meiosis the mitochondria of the spermatid collect along side the nucleus and fuse into two masses; these wrap around each other to produce the spherical Nebenkern. During flagellum elongation the Nebenkern unfolds and the two derivatives (major and minor mitochondrial derivatives) elongate down the axoneme. |
| Spot adherens junction | A small cell-cell adherens junction assembled during the cellularization stage of insect embyrogenesis; spot adherens junctions later fuse to form the zonula adherens. |
| potassium:proton antiporter complex | |
| Mucocyst | A small subcellular vesicle, surrounded by a membrane, in the pellicle of ciliate protozoans that discharges a mucus-like secretion. |
| Plasma membrane succinate dehydrogenase complex | |
| External side of apical plasma membrane | |
| MHC class Ib protein complex | A transmembrane protein complex composed of a MHC class Ib alpha chain and, in most cases, an invariant beta2-microglobin chain, and with or without a bound peptide or lipid antigen. Class Ib here refers to non-classical class I molecules, such as those of the CD1 or HLA-E gene families. |
| Hippocampal mossy fiber to CA3 synapse | |
| Sporoplasm | The complex infective apparatus corresponding to the central mass of cytoplasm within a spore that is injected into a host cell by various parasitic microorganisms. |
| Presynaptic endocytic zone membrane | |
| Vma12-Vma22 assembly complex | |
| BRCA1-Rad51 complex | A protein complex that contains BRCA1 and Rad 51, and is involved in the control of recombination and of genome integrity. |
| proton-transporting V-type ATPase, V0 domain | A protein complex that forms part of a proton-transporting V-type ATPase and mediates proton transport across a membrane. The V0 complex consists of at least four different subunits (a,c,d and e); six or more c subunits form a proton-binding rotor ring. |
| Parallel fiber to Purkinje cell synapse | |
| Rvs161p-Rvs167p complex | |
| Astrocyte end-foot | Terminal process of astrocyte abutting non-neuronal surfaces in the brain. |
| Gas vesicle | A hollow structure made of protein, which usually has the form of a cylindrical tube closed by conical end caps. By regulating their relative gas vesicle content aquatic microbes are able to perform vertical migrations. |
| Intrinsic component of external side of cell outer membrane | |
| Vacuolar proton-transporting V-type ATPase complex | A proton-transporting two-sector ATPase complex found in the vacuolar membrane, where it acts as a proton pump to mediate acidification of the vacuolar lumen. |
| Golgi medial cisterna | The middle Golgi cisterna (or cisternae). |
| Rhoptry membrane | The lipid bilayer surrounding a rhoptry. |
| Basal pole of outer hair cell | |
| EGFR-Shc-Grb2-Sos complex | A protein complex that contains the epidermal growth factor receptor (EGFR), Grb2, the adaptor protein SHC and the guanine nucleotide exchange factor Sos (or an ortholog thereof, such as mSos1), and is involved in linking EGFR activation to the p21-Ras pathway. |
| Mannan polymerase I complex | |
| Sperm end piece | The short tip of the sperm flagellum, adjacent to the sperm principal piece and furthest from the sperm head, which contains only the axoneme surrounded by the plasma membrane. |
| Phagocytic vesicle lumen | The volume enclosed by the membrane of a phagocytic vesicle. |
| insulin-like growth factor binary complex | A complex of two proteins, which in animals is 50kDa and consists of the insulin-like growth factor (IGF) and one of the insulin-like growth factor binding protein-1 (IGFBP-1), -2 (IGFBP-2), -4 (IGFBP-4) and -6 (IGFBP-6). The complex plays a role in growth and development. |
| Perinuclear endoplasmic reticulum membrane | |
| Trichocyst | A crystalline exocytotic organelle composed of small, acidic proteins existing primarily as disulphide-linked dimers. The trichocyst is an organelle that releases long filamentous proteins that capture predators in nets to slow them down when the cell is disturbed. The protein is nontoxic and shaped like a long, striated, fibrous shaft. |
| Cytoplasmic side of Golgi membrane | |
| Rough endoplasmic reticulum lumen | The volume enclosed by the membranes of the rough endoplasmic reticulum. |
| Cerebellar climbing fiber to Purkinje cell synapse | |
| Yolk plasma | Discrete structures that partition the water-soluble portion of the yolk of oocytes and ova, which may or may not be membrane enclosed. |
| Somatic spine | Spine emanating from the cell soma of a neuron. |
| Myosin XIII complex | |
| F bouton | Synaptic bouton found in the ventral horn of the spinal cord. F boutons range in diameter from 0.5 to 7 um and contain flattened or pleomorphic synaptic vesicles. |
| Mitotic spindle midzone | The area in the center of the anaphase spindle consisting of microtubules, microtubule bundling factors and kinesin motors where the spindle microtubules from opposite poles overlap in an antiparallel manner. |
| Polytene chromosome interband | A stretch of less tightly packed chromatin along the polytene chromosome, found between bands. |
| Alkanesulfonate monooxygenase complex | |
| Kinociliary basal body | |
| Scc2-Scc4 cohesin loading complex | |
| Neurofilament cytoskeleton | Intermediate filament cytoskeletal structure that is made up of neurofilaments. Neurofilaments are specialized intermediate filaments found in neurons. |
| BRE1 E3 ubiquitin ligase complex | |
| Nuclear cohesin complex | A cohesin complex required for cohesion between sister chromatids that remain in the nucleus. |
| DnaA-HU complex | |
| Chloroplast outer membrane translocon | |
| Cytosolic tRNA wobble base thiouridylase complex | A complex of two proteins involved in the thiolation of U34 in glutamate, lysine, and glutamine tRNAs of eukaryotes. |
| Postsynapse of neuromuscular junction | |
| Phagocytic cup base | |
| Hydrogenosomal membrane | The lipid bilayer surrounding a hydrogenosome. |
| Mastigoneme | |
| Luminal surveillance complex | A multiprotein complex that recognizes ERAD-luminal misfolded substrates and brings them to the ubiquitination/extraction machinery. In yeast, this complex consists of Yos9p, Kar2p and Hrd3p proteins. |
| Lewy body corona | The periphery of a Lewy body. In Parkinson's disease, it contains spherical accumulations of filaments arranged in a loose, radiating array. |
| NAD(P)H dehydrogenase complex (plastoquinone) | |
| Secretory IgA immunoglobulin complex | A polymeric IgA immunoglobulin complex that is complexed with one chain of secretory component (SC). Polymeric IgA is present in mucosal areas, having been transported via a transcytosis mechanism in mucosal epithelial cells relying on the polymeric Ig receptor, a portion of which then remains bound to the polymeric IgA as secretory component. |
| Foot layer | The inner layer of the ectexine. |
| asymmetric, glutamatergic, excitatory synapse | |
| Derlin-1-VIMP complex | |
| Cerebellar mossy fiber | An axon arising from cerebellar projecting cells in the cochlea, vestibular nuclei, spinal cord, reticular formation, cerebellar nuclei and basilar pontine nuclei. Mossy fibers enter through all three cerebellar peduncles and send collaterals to the deep cerebellar nuclei, then branch in the white matter and terminate in the granule cell layer. Through this branching, a given mossy fiber can innervate several folia. Mossy fibers synapse on granule cells. The synaptic contacts are made at enlargements along the length of the mossy fiber called mossy fiber rosettes. The enlargements of the rosettes give the axons as mossy appearance in Golgi stained preparations. |
| Intercalary heterochromatin | Any of the regions of heterochromatin that form a reproducible set of dense bands scattered along the euchromatic arms in polytene chromosomes. |
| Hyphal septin ring | |
| Myosin XIV complex | A myosin complex containing a class XIV myosin heavy chain and associated light chains; myosin XIV heavy chains are the simplest known, containing a motor domain, no classic IQ motif and variable length tails. |
| Integral component of synaptic vesicle membrane | The component of the synaptic vesicle membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Anchored component of synaptic vesicle membrane | |
| Bacterial thylakoid | |
| Plasma membrane-derived thylakoid membrane | |
| Nucleoplasmic THO complex | |
| ProVWX complex | |
| syntaxin-6-syntaxin-16-Vti1a complex | A SNARE complex that contains syntaxin 6, syntaxin 16, and Vti1a (or orthologs thereof). |
| Sperm individualization complex | A macromolecular complex that includes cytoskeletal components and part of the cell membrane. Forms at the nuclear end of a male germline syncytium, or cyst, and translocates the over the length of the syncytium in the course of sperm individualization. Each complex contains an array of 64 investment cones, one per nucleus, that move synchronously along the spermatogenic cyst. |
| Cytoplasmic microtubule minus-end | |
| Proximal portion of axoneme | |
| ficolin-1-rich granule | |
| Synaptic vesicle lumen | The volume enclosed by the synaptic vesicle membrane. |
| Neuron projection branch point | |
| Dendritic branch point | The part of a dendrite where the cell projection branches, giving rise to a dendritic branch. |
| Cytoplasmic cyclin-dependent protein kinase holoenzyme complex | Cyclin-dependent protein kinase (CDK) complex found in the cytoplasm. |
| Amorphous vesicle | A cytoplasmic membrane-bounded vesicle first described in dendrites, categorized by smooth membranes, electron-lucent interiors and irregular shapes. Sometimes occurs in clumps. Amorphous vesicles have been found to contain material taken up from the extracellular space, therefore suggesting that they may be part of the endosomal pathway. |
| Specific granule lumen | |
| Primary cell wall cellulose synthase complex | |
| bacterial-type flagellum basal body | One of the three major substructures of the flagellin-based flagellum; a structure consisting of a rod, a series of rings, the Mot proteins, the switch complex and the flagellum-specific export apparatus. The rings anchor the flagellum to the cytoplasmic membrane (MS ring), the peptidoglycan (P ring) and the outer membrane (L ring). Examples of this component are found in bacteria. |
| alphaV-beta3 integrin-EGFR complex | A protein complex that consists of an alphaV-beta3 integrin complex bound to epidermal growth factor receptor. |
| Ectexine | The outer part of the exine, which stains positively with basic fuchsin in optical microscopy and has higher electron density in conventionally prepared TEM sections. |
| Acid phosphatase complex | |
| eif4e-cup complex | |
| Bacterial outer membrane vesicle | |
| HFE-transferrin receptor complex | |
| Holliday junction helicase complex | |
| Dendritic spine membrane | The portion of the plasma membrane surrounding a dendritic spine. |
| endospore-forming forespore | |
| phenylacetyl-CoA 1,2-epoxidase complex | |
| Amyloplast envelope | The double lipid bilayer enclosing the amyloplast and separating its contents from the rest of the cytoplasm; includes the intermembrane space. |
| Intine | The innermost of the major layers of the pollen grain wall which underlies the exine and borders the cytoplasm. |
| Fibrillary inclusion | Cellular inclusion consisting of circular areas filled with fine slender filaments about 10 nanometers in diameter, delimited by a wall of varying complexity (either a single continuous membrane or a tubular network consisting of a fine filamentous material giving the wall a honeycomb appearance). Fibrillary inclusions are found in the cytoplasm of giant cells of Dieters in the lateral vestibular nucleus of the rat; similar structures have been described in the ventral cochlear nucleus, spinal cord, and substantia nigra. |
| Left nucleus | |
| Centriolar subdistal appendage | |
| Neuronal cell body membrane | The plasma membrane of a neuron cell body - excludes the plasma membrane of cell projections such as axons and dendrites. |
| Protein phosphatase inhibitor complex | |
| Nucleoplasmic periphery of the nuclear pore complex | |
| Nuclear envelope adjacent to nuclear pore complex | |
| DnaA-DnaB-DnaC complex | |
| Caveolar macromolecular signaling complex | A complex composed of proteins required for beta adrenergic receptor activation of protein kinase A. It includes the Cav 12. subunit of L-type calcium channel, protein kinase A regulatory subunit 2(PKAR2), adenyl cyclase, beta-adrenergic receptor, G-alpha-S, protein phosphatase 2A (PP2A) and caveolin 3 (CAV3). |
| Polymeric IgA immunoglobulin complex | A protein complex composed of two, three, or four monomeric IgA immunoglobulin complexes linked through both direct disulfide bonds and through disulfide binded monomers of J chain acting as a bridge. Each IgA monomer consists of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds. Dimeric IgA is sometimes complexed additionally with secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| laminin-522 complex | |
| formin-nucleated actin cable | |
| ERBB4:ERBB2 complex | |
| Subpellicular network | |
| Plasma membrane-derived chromatophore membrane | The lipid bilayer associated with a plasma membrane-derived chromatophore; surrounds chromatophores that form complete vesicles. |
| Integral component of lysosomal membrane | |
| Toll-like receptor 1-Toll-like receptor 2 protein complex | A heterodimeric protein complex containing Toll-like receptor 1 (TLR1) and Toll-like receptor 2 (TLR2). |
| MacAB-TolC complex | |
| Exopher | |
| Photoreceptor proximal connecting cilium | |
| Kir2 inward rectifier potassium channel complex | |
| Collagen sheet | |
| Actin body | |
| Neuromuscular junction of somatic muscle | |
| Sperm mitochondrial sheath | The tightly packed helical sheath of ATP-producing mitochondria restricted to the midpiece of the sperm flagellum. |
| Central region of growth cone | |
| CHOP-C/EBP complex | A heterodimeric protein complex that is composed of the transcription factor CHOP (GADD153) and a member of the C/EBP family of transcription factors. |
| Nbp35-Cfd1 ATPase complex | |
| Noradrenergic synapse | |
| succinate-CoA ligase complex (GDP-forming) | A heterodimeric enzyme complex, usually composed of an alpha and beta chain. Functions in the TCA cycle, hydrolyzing succinyl-CoA into succinate and CoA, thereby forming GTP. |
| Half bridge of spindle pole body | |
| IgA immunoglobulin complex, circulating | A protein complex composed of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds, sometimes complexed with J chain or J chain and secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| network-forming collagen trimer | A collagen trimer that forms networks. |
| bacterial-type flagellum basal body, rod | |
| Anchored component of presynaptic membrane | |
| Clathrin coat of synaptic vesicle | |
| Anchored component of synaptic membrane | |
| Cbf1-Met4-Met28 complex | |
| Nematosome | Cytoplasmic, ball-like inclusion resembling a nucleolus and consisting of a convoluted network of electron-opaque strands embedded in a less dense matrix. It measures approximately 0.9 microns and lacks a limiting membrane. Its strands (diameter = 400-600 A) appear to be made of an entanglement of tightly packed filaments and particles approximately 25-50 A thick. Cytochemical studies suggest the presence of nonhistone proteins and some RNA. Usually only one such structure is present in a cell, and it appears to occur in most ganglion cells. Although they can be seen anywhere in the cell body, nematosomes are typically located in the perinuclear cytoplasm, where they are often associated with smooth-surfaced and coated vesicles. |
| Basal distal dendrite | |
| Major mitochondrial derivative | |
| Spine mat | A configuration of neuron spines found on ciliary ganglion neurons in the embryonic and adult brain consisting of patches of closely spaced spines lying flat against the soma. |
| Calcium ion-transporting ATPase complex | Protein complex that carries out the reaction: ATP + H2O + Ca2+(out) = ADP + phosphate + Ca2+(in). |
| Integral component of presynaptic active zone membrane | |
| Cyanelle | A plastid that contains unstacked, phycobilisome-bearing thylakoid membranes and is surrounded by a double membrane with a peptidoglycan layer in the intermembrane space between the two envelope membranes. Cyanelles are characteristic of algae in the class Glaucophyta, and may represent an ancestral form of plastid. |
| Integral component of the cytoplasmic side of the plasma membrane | |
| laminin-5B complex | |
| serine-tRNA ligase complex | |
| Phosphatidylinositol 3-kinase complex, class III, type II | A class III phosphatidylinositol 3-kinase complex that is involved in vacuolar protein sorting (VPS) via endosomes. In budding yeast, this complex consists of Vps30p, Vps34p, Vps38 and Vps15p. |
| Anchored component of external side of plasma membrane | The component of the plasma membrane consisting of the gene products that are tethered to the external side of the membrane only by a covalently attached anchor, such as a lipid group embedded in the membrane. Gene products with peptide sequences that are embedded in the membrane are excluded from this grouping. |
| Homodimeric serine palmitoyltransferase complex | A homodimeric complex which transfers a palmitoyl group onto serine, forming 3-dehydro-D-sphinganine. |
| Tertiary granule membrane | The lipid bilayer surrounding a tertiary granule. |
| Ascus membrane | |
| Contractile vacuolar membrane | The lipid bilayer surrounding the contractile vacuole. |
| Active sex chromosome | |
| Nuclear pore central transport channel | The central substructure of the nuclear pore complex (NPC), through which nucleocytoplasmic transport of RNAs, proteins and small molecules occurs. The central transport channel is filled with FG-nucleoporins, which form a selective barrier and provide a series of binding sites for transporter proteins. Characterized S. cerevisiae FG-nucleoporins include Nup159p, Nup145Np, Nup116p, Nup100p, Nsp1p, Nup57p, Nup49p, Nup42p, Nup53p, Nup59p/Asm4p, Nup60p and Nup1. Characterized vertebrate FG-nucleoporins include Nup214, Nup98, Nup62, Nup54, Nup58/45, NLP1, and Nup153. |
| Carotenoid vesicle | |
| Anthranilate synthase complex | A heterotetrameric enzyme complex made up of two components I and two components II. Catalyzes the formation of anthranilate, pyruvate and L-glutamate from chorismate and L-glutamine. |
| alpha9-beta1 integrin-ADAM12 complex | A protein complex that consists of an alpha9-beta1 integrin complex bound to the transmembrane metallopeptidase ADAM12. |
| Recycling endosome lumen | |
| Minor mitochondrial derivative | |
| alpha5-beta1 integrin-endostatin complex | A protein complex that consists of an alpha5-beta1 integrin complex bound to endostatin, the NC1 domain of the alpha1 chain of type XVIII collagen. |
| Postsynaptic actin cytoskeleton | |
| IgZ immunoglobulin complex | |
| angiogenin-PRI complex | A stable heterodimer of angiogenin and placental ribonuclease inhibitor; interaction between angiogenin and PRI prevents angiogenin binding to its receptor to stimulate angiogenesis. |
| proton-transporting two-sector ATPase complex, catalytic domain | A protein complex that forms part of a proton-transporting two-sector ATPase complex and catalyzes ATP hydrolysis or synthesis. The catalytic domain (F1, V1, or A1) comprises a hexameric catalytic core and a central stalk, and is peripherally associated with the membrane when the two-sector ATPase is assembled. |
| Lumenal side of endosome membrane | |
| Cytoplasmic side of late endosome membrane | |
| Lumenal side of late endosome membrane | |
| NOXA-BCL-2 complex | A heterodimeric protein complex consisting of NOXA and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators. |
| Protein storage vacuole membrane | The lipid bilayer surrounding a protein storage vacuole. |
| phosphoenolpyruvate-dependent sugar phosphotransferase complex | |
| Excitatory neuromuscular junction | |
| SeqA-DNA complex | |
| Karyomere | A membrane-bound intermediate cleavage-stage structure of individual or groups of chromosomes that coalesces and fuses with other karyomeres to form a nucleus during interphase. Karyomere formation occurs in blastomeres undergoing rapid cell division. |
| U2-type catalytic step 2 spliceosome | |
| Polar nucleus | Either of two nuclei located centrally in a flowering plant embryo sac that eventually fuse to form the endosperm nucleus. |
| laminin-12 complex | |
| Cyanelle envelope | |
| Megasporocyte nucleus | The nucleus of a megasporocyte, a diploid cell that undergoes meiosis to produce four megaspores, and its descendents. |
| External side of plasma membrane | The leaflet of the plasma membrane that faces away from the cytoplasm and any proteins embedded or anchored in it or attached to its surface. |
| Chloroplast small ribosomal subunit | The small subunit of a ribosome contained within a chloroplast. |
| Plastid small ribosomal subunit | The smaller of the two subunits of a plastid ribosome. |
| Endosome lumen | The volume enclosed by the membrane of an endosome. |
| fungal-type vacuole membrane | |
| Core primosome complex | |
| DnaB-DnaG complex | |
| Parkin-FBXW7-Cul1 ubiquitin ligase complex | A ubiquitin ligase complex containing Parkin (PARK2), the F-box protein FBXW7 (also called SEL-10) and a cullin from the Cul1 subfamily; substrate specificity is conferred by the F-box protein. |
| Oral apparatus | Complex basket- or funnel-like structure used by the cell to collect food and channel it to the cytostome; includes specialized sub-structures made up of closely-spaced cilia and underlying basal bodies and fibrillar systems. |
| Translation initiation ternary complex | |
| IRE1-RACK1-PP2A complex | |
| nucleolus-associated heterochromatin | Dense particles of heterochromatin, consisting of a loosely twisted strand about 600 Angstrom thick, found associated with the nucleolus. |
| Male germ cell nucleus | The nucleus of a male germ cell, a reproductive cell in males. |
| Snt2C complex | |
| PET complex | |
| Sad1-Kms1 LINC complex | |
| MsbA transporter complex | |
| Intrinsic component of synaptic vesicle membrane | |
| laminin-7 complex | A laminin complex composed of alpha3, beta2 and gamma1 polypeptide chains. |
| PCSK9-AnxA2 complex | |
| DNA helicase A complex | |
| Sculpture element | |
| Cytoplasmic replication fork | |
| Cytoplasmic replisome | |
| Plastid intermembrane space | The region between the inner and outer lipid bilayers of the plastid envelope. |
| Rhoptry lumen | |
| Type II terminal bouton | |
| Presynaptic endosome | |
| Eukaryotic 80S initiation complex | A protein complex composed of the large and small ribosomal subunits, methionyl-initiatior tRNA, and the capped mRNA. The initiator tRNA is positioned at the ribosomal P site at the AUG codon corresponding to the beginning of the coding region. |
| Chloroplast large ribosomal subunit | The large subunit of a ribosome contained within a chloroplast. |
| Etioplast stroma | |
| Cul8-RING ubiquitin ligase complex | |
| Activated SUMO-E1 ligase complex | |
| Ventral disc | |
| Eukaryotic 48S preinitiation complex | A protein complex composed of the small ribosomal subunit, eIF3, eIF1A, methionyl-initiatior methionine and a capped mRNA. The complex is initially positioned at the 5'-end of the capped mRNA. |
| Antipodal cell nucleus | |
| Extrinsic component of external side of plasma membrane | The component of a plasma membrane consisting of gene products and protein complexes that are loosely bound to its external surface, but not integrated into the hydrophobic region. |
| Porous cell septum | A septum or cross wall which does not entirely span the space between two portions of cell wall and may contain a specialized central pore structure. A porous septum allows the movement of organelles and/or cytoplasm between compartments. |
| Dolipore septum | A septum, or cross-wall, between two portions of a cell or hypha; contains a central pore around which the septum is swollen to form a barrel-shaped structure; pore is covered on each side of the septum by a septal pore cap (parenthosome). |
| MalFGK2 complex | |
| Intraconoid microtubule | A microtubule located such that it threads through the conoid and projects through the polar ring. |
| Mesosome | An intracellular, often complex, membranous structure, sometimes with additional membranous lamellae inside, found in bacteria. They are associated with synthesis of DNA and secretion of proteins. |
| rDNA protrusion | |
| Megasome | Large, cysteine proteinase rich lysosomes, often found in the amastigote (an intracytoplasmic, nonflagellated form of the parasite) stage of Leishmania species belonging to the mexicana complex. |
| Cell hair | A long, thin cell projection that contains F-actin and tubulin, with microtubules centrally located and F-actin peripherally located. |
| Polytene chromosome band | A stretch of densely packed chromatin along the polytene chromosome, visible as a morphologically distinct band. |
| Cdc48p-Npl4p-Vms1p AAA ATPase complex | |
| FMN reductase complex | |
| Simple sieve plate | |
| Postsynaptic density membrane | |
| Polytene chromosome chromocenter | A region at which the centric regions of polytene chromosomes are joined together. |
| Urease activator complex | |
| Maltose transport complex | |
| Lysosomal matrix | |
| peri-centrosomal recycling endosome | |
| Chloroplast ribulose bisphosphate carboxylase complex | A complex, located in the chloroplast, containing either both large and small subunits or just small subunits which carries out the activity of producing 3-phosphoglycerate from carbon dioxide and ribulose-1,5-bisphosphate. An example of this component is found in Arabidopsis thaliana. |
| Cytoplasmic side of lysosomal membrane | |
| clathrin-sculpted gamma-aminobutyric acid transport vesicle | A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release and containing gamma-aminobutyric acid transport vesicle. |
| RNA polymerase II termination complex | |
| Mossy fiber rosette | A synapse of a mossy fiber onto the dendrite of a granule cell; each mossy fiber can have up to 50 rosettes. |
| high-affinity iron permease complex | A protein complex composed of a multicopper ferroxidase that oxidizes Fe(II) to Fe(III), and a ferric iron permease that transports the produced Fe(III) into the cell. In high-affinity transport the transporter is able to bind the solute even if it is only present at very low concentrations. |
| Pollen aperture | |
| U12-type precatalytic spliceosome | |
| DnaA-Hda complex | |
| Cortical microtubule plus-end | |
| Actin cytoskeleton-regulatory complex | |
| Collagen type IV trimer | A collagen heterotrimer containing type IV alpha chains; [alpha1(IV)]2alpha2(IV) trimers are commonly observed, although more type IV alpha chains exist and may be present in type IV trimers; type IV collagen triple helices associate to form 3 dimensional nets within basement membranes. |
| Thioglucosidase complex | A large (200-800 kDa) multiprotein complex formed by 70-kDa and 5-kDa myrosinases, myrosinase- binding proteins (MBPs), MBP-related proteins and myrosinase-associated proteins. The complex has been identified in Brassica napus seeds. |
| Nexine | |
| Endospore coat | The layer in a bacterial endospore that lies under the exosporium, and is impermeable to many toxic molecules. The coat may also contain enzymes that are involved in endospore germination. |
| NuA3 histone acetyltransferase complex | A Gcn5-independent multisubunit complex that catalyzes the acetylation of histone H3. The budding yeast complex includes Sas3p, Taf30p, and Yng1p. |
| MIH complex | |
| Nsk1-Dlc1 complex | |
| Histone H3-containing nucleosome | |
| Lipopolysaccharide transport system | |
| Dense nuclear body | A location in the host cell nucleus where viral proteins colocalize late in infection prior to the onset of viral DNA synthesis. More than one site can be present simultaneously. |
| Amyloplast membrane | Either of the lipid bilayers that surround an amyloplast and form the amyloplast envelope. |
| Membrane stack | A configuration of endoplasmic reticulum (ER) found in Purkinje cells in the cerebellum and in axons in the lateral vestibular nucleus, consisting of parallel and interconnecting tubules whose outer surfaces are covered by particles or ringlike structures. |
| Basement membrane collagen trimer | Any collagen timer that is part of a basement membrane. |
| Bacterial extracellular vesicle | |
| Lumenal side of lysosomal membrane | |
| Myosin XVII complex | |
| ABIN2-NFKB1-MAP3K8 complex | A protein complex that contains the precursor form of NF-kappaB (p105), the NF-kappaB inhibitor ABIN-2, and the kinase TPL-2 (MAP3K8); the complex stabilizes TPL-2 and is involved in signaling in lipopolysaccharide (LPS)-stimulated macrophages. |
| Collagen type VI trimer | A collagen heterotrimer containing type VI alpha chains in alpha1(VI)alpha2(VI)alpha3(VI) trimers; type VI collagen triple helices associate to form beaded fibrils. |
| Axonal spine | A spine that originates from the axon, usually from the initial segment. |
| Protein C inhibitor-PLAT complex | A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and tissue-type plasminogen activator (PLAT); formation of the complex inhibits the serine protease activity of tissue-type plasminogen activator. |
| Schaffer collateral - CA1 synapse | |
| BAD-BCL-xl complex | A heterodimeric protein complex consisting of BAD and BCL-xl, members of the Bcl-2 family of anti- and proapoptotic regulators. |
| clathrin-sculpted vesicle | A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release. |
| Leucosome | A tissue-specific, membrane-bounded cytoplasmic organelle within which uric acid and/or purines crystalize in reflective stacks. Leucosomes are synthesized in leucophore cells and have a whitish cast. |
| Cochlear hair cell ribbon synapse | |
| Grb2-SHP-2 complex | A protein complex that contains the receptor adaptor proteins Grb2 and SHP-2, and is involved signaling via the PDGFR signaling pathway. |
| Intrinsic component of the cytoplasmic side of the plasma membrane | The component of a plasma membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor) which is embedded in the cytoplasmic side of the plasma membrane only. |
| Nucleoplasmic side of nuclear pore | |
| Chloroplast intermembrane space | The region between the inner and outer lipid bilayers of a chloroplast envelope. |
| Other organism part | Any constituent part of a secondary organism with which the first organism is interacting. |
| Intrinsic component of external side of plasma membrane | The component of a plasma membrane consisting of gene products and protein complexes that penetrate the external side of the plasma membrane only, either directly or via some covalently attached hydrophobic anchor. |
| Postsynaptic density, intracellular component | |
| D-amino-acid dehydrogenase complex | |
| Collagen type V trimer | A collagen heterotrimer containing type V alpha chains; [alpha1(V)]2alpha2(V) and alpha1(V)alpha2(V)alpha3(V) trimers have been observed; type V collagen triple helices associate to form fibrils. |
| CA3 pyramidal cell dendrite | |
| short-chain collagen trimer | Any collagen trimer that does not form fibrils and that is relatively short compared to the collagen trimers that do form fibrils. |
| Peg and socket contact | |
| Kibra-Ex-Mer complex | |
| Plastid large ribosomal subunit | The larger of the two subunits of a plastid ribosome. Two sites on the ribosomal large subunit are involved in translation: the aminoacyl site (A site) and peptidyl site (P site). |
| spectrin-associated cytoskeleton | The part of the cytoskeleton composed of spectrin, protein 4.1 and ankyrin. Spectrin-associated cytoskeleton is associated with the plasma membrane. |
| Toll-like receptor 2-Toll-like receptor 6 protein complex | A heterodimeric protein complex containing Toll-like receptor 2 (TLR2) and Toll-like receptor 6 (TLR6). |
| Recurrent axon collateral | Axon collateral that ramifies in the area of the soma of the cell of origin. |
| Microneme membrane | The lipid bilayer surrounding a microneme. |
| Uropod membrane | The portion of the plasma membrane surrounding a uropod. |
| Cone photoreceptor disc membrane | |
| Endospore core | |
| Integral component of chloroplast inner membrane | |
| Collagen anchoring fibril | |
| Integral component of plastid membrane | |
| Intrinsic component of plastid inner membrane | |
| Integral component of plastid inner membrane | |
| Intrinsic component of chloroplast inner membrane | |
| Basal pole of neuron | Portion of a neuron cell soma closest to the point where the basilar dendrite emerges. |
| Cyclin A1-CDK1 complex | |
| APC-tubulin-IQGAP1 complex | A protein complex that contains the tumor suppressor protein adenomatous polyposis coli (APC), alpha-tubulin, gamma-tubulin, and the Rac1 and Cdc42 effector IQGAP1; may play a role in cytoskeleton organization. |
| Microneme lumen | The volume enclosed by the microneme membrane. |
| Leucoplast | A colorless plastid involved in the synthesis of monoterpenes. |
| alpha4-beta1 integrin-JAM2 complex | A protein complex that consists of an alpha4-beta1 integrin complex bound to the cell adhesion molecule JAM2. |
| Proteinoplast | A leucoplast in which protein is stored. |
| Subapical part of cell | |
| dolichyl-phosphate-mannose-protein mannosyltransferase Pmt4p homodimer complex | |
| dolichyl-phosphate-mannose-protein mannosyltransferase Pmt5p-Pmt3p dimer complex | |
| dolichyl-phosphate-mannose-protein mannosyltransferase Pmt1p-Pmt3p dimer complex | |
| mBAF complex | |
| laminin-14 complex | |
| alphav-beta3 integrin-IGF-1-IGF1R complex | A protein complex that consists of an alphav-beta3 integrin complex bound to insulin-like growth factor-1 (IGF-1) and type I insulin-like growth factor receptor (IGF1R). IGF1R is a heterotetramer that consists of two alpha-subunits and two beta-subunits. |
| Actin cytoskeleton of dendritic spine | |
| Cellular bud neck contractile ring | |
| Mitotic actomyosin contractile ring | |
| Generative cell nucleus | The nucleus of the generative cell, a cell contained within the pollen grain that will divide to produce two haploid sperm cells. |
| alpha6-beta1 integrin-CD151 complex | A protein complex that consists of an alpha6-beta1 integrin complex bound to the tetraspanin CD151. |
| Gerontoplast | A plastid found in senescing, formerly green tissues that is derived from a chloroplast that undergoes an organized developmental program of senescence. |
| Chloroplastic endopeptidase Clp complex | |
| Intrinsic component of presynaptic active zone membrane | |
| alphaIIb-beta3 integrin-fibronectin-tissue transglutaminase complex | A protein complex that consists of an alphaIIb-beta3 integrin complex bound to fibronectin and tissue transglutaminase. |
| Tor2-Mei2-Ste11 complex | |
| Postsynaptic specialization membrane | |
| Thiazole synthase complex | |
| Leucoplast stroma | |
| Cytoplasmic microtubule plus-end | |
| Pectic matrix | The gel-like pectin matrix consists of the interlinked acidic and neutral pectin networks that are further cross-linked by calcium bridges. Pectins consist largely of long chains of mostly galacturonic acid units (typically 1,4 linkages and sometimes methyl esters). Three major pectic polysaccharides (homogalacturonan, rhamnogalacturonan I and rhamnogalacturonan II) are thought to occur in all primary cell walls. |
| Mitochondrial proton-transporting ATP synthase complex, coupling factor F(o) | All non-F1 subunits of the mitochondrial hydrogen-transporting ATP synthase, including integral and peripheral mitochondrial inner membrane proteins. |
| Muscle thin filament tropomyosin | A form of the tropomyosin dimer found associated with actin and the troponin complex in muscle thin filaments. |
| Type II site-specific deoxyribonuclease complex | |
| Gut granule membrane | |
| Investment cone | A cytoskeletal part that consists of a microfilament-rich cone that forms round each nucleus in a spermatogenic cyst and translocates the length of the cyst during sperm individualization. |
| Signal recognition particle, chloroplast targeting | |
| Synaptic vesicle protein transport vesicle | |
| Curli secretion complex | |
| Late endosome lumen | The volume enclosed by the membrane of a late endosome. |
| Chloroplast photosystem I | Photosystem located in the chloroplast that functions as a light-dependent plastocyanin-ferredoxin oxidoreductase, transferring electrons from plastocyanin to ferredoxin. An example of this is found in Arabidopsis thaliana. |
| Fungal biofilm matrix | |
| Spindle pole centrosome | A centrosome from which one pole of a mitotic or meiotic spindle is organized. |
| platelet-derived growth factor receptor-ligand complex | |
| Junctional sarcoplasmic reticulum membrane | The part of the sarcoplasmic reticulum membrane that contains calcium release channels, is devoted to calcium release and is juxtaposed to transverse tubule membrane. The junctional sarcoplasmic reticulum membrane consists of the junctional region of the terminal cisterna membrane. |
| Synaptobrevin 2-SNAP-25-syntaxin-1a complex | A SNARE complex that contains synaptobrevin 2 (VAMP2), SNAP-25, and syntaxin 1a (or orthologs thereof). |
| Antipodal site | |
| THO complex part of transcription export complex | The THO complex when it is part of the TREX (TRanscription EXport) complex that is involved in coupling transcription to export of mRNAs to the cytoplasm. In S. cerevisiae, it is composed of four subunits: Hpr1, Tho2, Thp1, and Mft1, while the human complex is composed of 7 subunits. |
| Outer membrane-bounded periplasmic space | |
| Platelet dense tubular network membrane | The lipid bilayer surrounding the platelet dense tubular network. |
| Shc-EGFR complex | A protein complex that contains the epidermal growth factor receptor (EGFR) and the adaptor protein Shc, and is involved in linking EGFR activation to the p21-Ras pathway. |
| EGFR:ERBB2 complex | |
| Collagen type I trimer | A collagen trimer containing alpha(I) chains. The most common form of type I collagen is a heterotrimer containing two alpha1(I) chains and one alpha2(I) chain; homotrimers containing three alpha1(I) chains are also found. Type I collagen triple helices associate to form banded fibrils. |
| Type III site-specific deoxyribonuclease complex | |
| Ferredoxin hydrogenase complex | |
| Catalytic step 2 spliceosome | A spliceosomal complex that contains three snRNPs, including U5, bound to a splicing intermediate in which the first catalytic cleavage of the 5' splice site has occurred. The precise subunit composition differs significantly from that of the catalytic step 1, or activated, spliceosome, and includes many proteins in addition to those found in the associated snRNPs. |
| Phagolysosome membrane | The lipid bilayer surrounding a phagolysosome. |
| Cvt vesicle membrane | |
| Smooth septate junction | A septate junction that lacks the regular arrays of electron-dense septae found in pleated septate junctions. |
| Spitzenkorper | Structure within the hyphal tip of filamentous fungi that acts as an organizing center for hyphal tip growth; may function to supply vesicles to the elongating tip and/or to organize cytoskeletal microfilaments. |
| Elaioplast | A leucoplast in which oil is stored. |
| Postsynaptic endocytic zone membrane | |
| trans-Golgi network membrane | The lipid bilayer surrounding any of the compartments that make up the trans-Golgi network. |
| MECO complex | A highly stable complex composed of the ATAC complex and the mediator complex (also called TRAP or MED). MECO binds and regulates the transcription of a subset of non-coding RNAs transcribed by RNA polymerase II. |
| Integral component of vacuolar membrane | |
| Intrinsic component of vacuolar membrane | |
| Cell cortex of cell tip | |
| Primary plasmodesma | |
| Postsynaptic specialization, intracellular component | |
| Basal labyrinth | A region in the lower half of some cells formed from extensive infoldings of the basal plasma membrane; includes cytoplasm adjacent to the infolded membrane. |
| beta-catenin-ICAT complex | |
| BAD-BCL-2 complex | A heterodimeric protein complex consisting of BAD and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators. |
| interleukin4-interleukin-4 receptor complex | A protein complex that is formed by the association of a heterodimeric interleukin-4 receptor complex with an interleukin-4 molecule. |
| HU-DNA complex | |
| Pho85-Pho80 CDK-cyclin complex | |
| Extrinsic component of endosome membrane | The component of an endosome membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| Integral component of postsynaptic density membrane | |
| Ethanolamine degradation polyhedral organelle | |
| Plasmodesmatal desmotubule | |
| Plasmodesmatal endoplasmic reticulum | |
| Acetate CoA-transferase complex | |
| Anchored component of membrane | The component of a membrane consisting of the gene products that are tethered to the membrane only by a covalently attached anchor, such as a lipid group that is embedded in the membrane. Gene products with peptide sequences that are embedded in the membrane are excluded from this grouping. |
| Symbiont cell surface | |
| Amphisome membrane | |
| Ocelloid | |
| Glomerular endothelium fenestra | A large plasma membrane-lined circular pore that perforates the flattened glomerular endothelium and, unlike those of other fenestrated capillaries, is not spanned by diaphragms; the density and size of glomerular fenestrae account, at least in part, for the high permeability of the glomerular capillary wall to water and small solutes. |
| Apical lamina of hyaline layer | A fibrous network that is part of the hyalin layer extracellular matrix. The apical lamina is thought to be principally composed of the glycoproteins fibropellins. This matrix has been found in echinoderms. |
| Myosin VIII complex | A myosin complex containing a dimer of class VIII myosin heavy chains and associated light chains. Myosin VIII is predicted to be dimeric, and contain an unusual 100-190 residue N-terminal extension prior to their motor domains, 3-4 IQ motifs, a short region (~70 residues) of predicted alpha-helical coiled coil and a C-terminal domain. |
| Alveolar lamellar body | A specialized secretory organelle found in type II pneumocytes and involved in the synthesis, secretion, and reutilization of pulmonary surfactant. |
| Proteasome regulatory particle, base subcomplex | The subcomplex of the proteasome regulatory particle that directly associates with the proteasome core complex. |
| proton-transporting two-sector ATPase complex, proton-transporting domain | A protein complex that forms part of a proton-transporting two-sector ATPase complex and carries out proton transport across a membrane. The proton-transporting domain (F0, V0, or A0) includes integral and peripheral membrane proteins. |
| laminin-3 complex | A laminin complex composed of alpha1, beta2 and gamma1 polypeptide chains. |
| Sexual spore wall | |
| Apical proximal dendrite | |
| Chloroplast chromosome | A circular DNA molecule containing chloroplast encoded genes. |
| Tertiary granule lumen | |
| Septin band | A diffuse ring composed of a series of septin bars that run parallel to the long axis of the cell. This type of septin structure has been observed in a number of locations associated with polarized grown and/or deposition of new membrane, but not with cytokinesis, such as at the shmoo (mating projection) neck, at the junction between the mother cell and the germ tube (hypha) of a fungal cell growing filamentously. |
| Intrinsic component of postsynaptic density membrane | |
| Right anterior flagellum | |
| Cell trailing edge membrane | The portion of the plasma membrane surrounding the trailing edge of a motile cell. |
| Aminodeoxychorismate synthase complex | |
| host-symbiont bicellular tight junction | |
| 7,8-didemethyl-8-hydroxy-5-deazariboflavin synthase complex | |
| MUB1-RAD6-UBR2 ubiquitin ligase complex | |
| Cytoplasmic side of mitochondrial outer membrane | The external (cytoplasmic) face of the mitochondrial outer membrane. |
| Type II protein secretion system complex | A large protein complex, containing 12-15 subunits, that spans the cell envelope of Gram-negative bacteria and mediates the movement of proteins into the extracellular environment. The complex includes a component in the cytoplasm, an inner membrane subcomplex that reaches into the periplasmic compartment and a secretion pore in the outer membrane. Proteins using the Type II pathway are transported across the cytoplasmic membrane by the Sec or Tat complex. |
| Methionyl glutamyl tRNA synthetase complex | |
| Cyclin D2-CDK6 complex | A protein complex consisting of cyclin D2 and cyclin-dependent kinase 6 (CDK6). Cyclins are characterized by periodicity in protein abundance throughout the cell cycle. Cyclin-dependent kinases represent a family of serine/threonine protein kinases that become active upon binding to a cyclin regulatory partner. |
| Presynaptic actin cytoskeleton | |
| Vacuolar proton-transporting V-type ATPase, V1 domain | The V1 domain of a proton-transporting V-type ATPase found in the vacuolar membrane. |
| calcium:proton antiporter complex | |
| Mad-Max-mSin3A complex | A transcriptional repressor complex that contains a heterodimer of the bHLH-ZIP proteins Mad and Max, plus mSin3A, a homolog of the yeast Sin3p. |
| beta-heterochromatin | A diffusely banded region of heterochromatin located between euchromatin and alpha-heterochromatin in the polytene chromosome chromocenter; normally replicated during polytenization. |
| Chloroplast stromal thylakoid | |
| sheet-forming collagen trimer | sheet-forming collagen trimer |
| proton-transporting ATP synthase complex, coupling factor F(o) | All non-F1 subunits of a hydrogen-transporting ATP synthase, including integral and peripheral membrane proteins. |
| Anchored component of plasma membrane | The component of the plasma membrane consisting of the gene products that are tethered to the membrane only by a covalently attached anchor, such as a lipid group, that is embedded in the membrane. Gene products with peptide sequences that are embedded in the membrane are excluded from this grouping. |
| SOD1-Bcl-2 complex | |
| Glycosome lumen | The volume enclosed by the membrane of a glycosome. |
| Alveolar lamellar body membrane | The lipid bilayer surrounding an alveolar lamellar body, a specialized secretory organelle found in type II pneumocytes and involved in the synthesis, secretion, and reutilization of pulmonary surfactant. |
| Mitochondrial proton-transporting ATP synthase complex, catalytic sector F(1) | |
| Plasma membrane respiratory chain complex I | A subcomplex of the respiratory chain located in the plasma membrane. It contains about 25 different polypeptide subunits, including NADH dehydrogenase (ubiquinone), flavin mononucleotide and several different iron-sulfur clusters containing non-heme iron. The iron undergoes oxidation-reduction between Fe(II) and Fe(III), and catalyzes proton translocation linked to the oxidation of NADH by ubiquinone. Examples of this component are found in bacterial species. |
| Dinoflagellate peduncle | |
| Attachment organelle | A membrane-bounded extension of the cell, originally characterized in Mycoplasma species, that contains an electron-dense core that is part of the cytoskeleton and is oriented lengthwise and ends distally in a bulbous knob (terminal button). Required for adherence to host cells and involved in gliding motility and cell division. |
| DNA topoisomerase IV complex | |
| Cell body membrane | The plasma membrane of a cell that bears surface projections such as axons, dendrites, cilia, or flagella, excluding the plasma membrane on cell projections. |
| Transverse flagellum | |
| Ubp3-Bre5 deubiquitination complex | |
| Presynaptic cytosol | |
| Integral component of peroxisomal membrane | The component of the peroxisomal membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Endocytic vesicle lumen | The volume enclosed by the membrane of an endocytic vesicle. |
| Interferon regulatory factor 3-interferon regulatory factor 7 complex | An interferon regulatory factor complex that consists of a heterodimer of interferon regulatory factor 3 and interferon regulatory factor 7. |
| Polysomal ribosome | A ribosome bound to mRNA that forms part of a polysome. |
| Cytoplasmic microtubule bundle | |
| S bouton | Synaptic bouton found in the ventral horn of the spinal cord. S boutons range in diameter from 0.5 to 8 um and contain spherical synaptic vesicles. |
| Striated muscle dense body | |
| Postsynaptic recycling endosome | |
| Basal proximal dendrite | |
| Rhabdomere microvillus | Thin cylindrical membrane-covered projection on the surface of a rhabdomere. |
| Dendrite membrane | The portion of the plasma membrane surrounding a dendrite. |
| Polyadic synapse | |
| Postsynaptic intermediate filament cytoskeleton | |
| Integral component of postsynaptic membrane | |
| Hippocampal mossy fiber expansion | |
| Intrinsic component of autophagosome membrane | |
| Integral component of autophagosome membrane | |
| Interferon regulatory factor 3-interferon regulatory factor 5 complex | |
| Anchored component of presynaptic active zone membrane | |
| Sulfite reductase complex (NADPH) | |
| Glyoxysomal membrane | The lipid bilayer surrounding a glyoxysome. |
| Azurophil granule membrane | The lipid bilayer surrounding an azurophil granule, a primary lysosomal granule found in neutrophil granulocytes that contains a wide range of hydrolytic enzymes and is released into the extracellular fluid. |
| multi-eIF complex | A multifactor complex composed of multiple translation initiation factors and the initiatior tRNAiMet, which is ready to bind to the small (40S) ribosome to form the 43S preinitiation complex. In S. cerevisiae, this complex is composed of eIF1, eIF2, eIF3, and eIF5. |
| Cytoproct | Stable, specialized structure for extrusion of waste by the cell into the surrounding medium. |
| Integral component of postsynaptic specialization membrane | |
| Pellicular membrane | |
| Mitochondrial intracristal space | |
| Cytoplasmic side of early endosome membrane | The side (leaflet) of the early endosome membrane that faces the cytoplasm. |
| Glial limiting end-foot | Terminal process of astrocyte that extends to the surface of the central nervous system. Together, glial limiting end-feet form the glial limiting membrane or glia limitans. |
| Blepharoplast | |
| Longitudinal flagellum | |
| alphaIIb-beta3 integrin-talin complex | A protein complex that consists of an alphaIIb-beta3 integrin complex bound to talin. |
| Cyanelle membrane | |
| Cyanelle stroma | |
| Cyanelle inner membrane | |
| Reservosome lumen | |
| Intrinsic component of postsynaptic membrane | |
| tRNA (m1A) methyltransferase complex | A protein complex involved in the catalysis of the formation of the modified nucleotide 1-methyladenosine (m1A) in tRNA. In yeast, it is a heterotetramer of two subunits, Gcd10p and Gcd14p, while in bacteria and archaea it is a homotetramer. |
| bBAF complex | |
| bacterial-type flagellum hook-filament junction | |
| alpha5-beta1 integrin-fibronectin-tissue transglutaminase complex | A protein complex that consists of an alpha5-beta1 integrin complex bound to fibronectin and tissue transglutaminase. |
| Dynamic microtubule bundle | |
| Mitochondrial proton-transporting ATP synthase, catalytic core | The hexamer, comprising three alpha and three beta subunits, that possesses the catalytic activity of the mitochondrial hydrogen-transporting ATP synthase. |
| proton-transporting ATP synthase, catalytic core | The hexamer that possesses the catalytic activity of the mitochondrial hydrogen-transporting ATP synthase. |
| Micropinosome | A membrane-bounded, uncoated intracellular vesicle formed by the process of micropinocytosis. |
| Intrinsic component of mitochondrial outer membrane | The component of the mitochondrial outer membrane consisting of the gene products that have some covalently attached part (e.g. peptide sequence or GPI anchor) which spans or is embedded in one or both leaflets of the membrane. |
| Extrinsic component of mitochondrial inner membrane | The component of mitochondrial inner membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| Early phagosome membrane | The lipid bilayer surrounding an early phagosome. |
| E.F.G complex | A protein complex that comprises three core spliceosomal proteins, designated E, F, and G. Formation of the E.F.G complex is essential but not sufficient for the formation of a stable U1 snRNP complex. |
| Etioplast prolamellar body | A three dimensional regular lattice found in etioplasts. It is composed of a continuous system of tubules but when exposed to light the symmetrical arrangement is rapidly lost as tubules become pinched off into two dimensional sections of lattice. These for perforated sheets of membrane that move apart, extend and increase, finally establishing the typical granal and intergranal lamellae of the mature chloroplast. |
| Transcription factor TFTC complex | A protein complex that does not contain either a TATA-binding protein (TBP) or a TBP-like factor, but is composed of several TAFIIs and other proteins, including a histone acetyltransferase. This complex is able to nucleate transcription initiation by RNA polymerase II, can mediate transcriptional activation, and has histone acetyltransferase activity. |
| Nucleus leading edge | |
| Postsynaptic cytosol | |
| Intrinsic component of postsynaptic specialization membrane | |
| EGFR-Grb2-Sos complex | A protein complex that contains the epidermal growth factor receptor (EGFR), Grb2 and the guanine nucleotide exchange factor Sos (or an ortholog thereof, such as mSos1), and is involved in linking EGFR activation to the p21-Ras pathway. |
| Spore inner membrane | |
| Rpd3L-Expanded complex | |
| Dendritic growth cone | The migrating motile tip of a growing nerve cell dendrite. |
| Reservosome matrix | |
| Chromoplast inner membrane | |
| Medial layer of collagen and cuticulin-based cuticle extracellular matrix | |
| Meiotic spindle midzone | |
| Perinucleolar chromocenter | A chromocenter adjacent to the nucleolus. |
| Cytoskeleton of dendritic spine | |
| Plasma membrane proton-transporting V-type ATPase complex | |
| Apical distal dendrite | |
| Actin filament branch point | |
| Mitotic nuclear membrane microtubule tethering complex | |
| Apicomedial cortex | |
| alpha3-beta1 integrin-CD151 complex | A protein complex that consists of an alpha3-beta1 integrin complex bound to the tetraspanin CD151. |
| laminin-9 complex | A laminin complex composed of alpha4, beta2 and gamma1 polypeptide chains. |
| NMDA selective glutamate receptor complex | |
| Dendrite cytoplasm | All of the contents of a dendrite, excluding the surrounding plasma membrane. |
| Transcription ternary complex | |
| Virion transport vesicle | |
| Integral component of nuclear inner membrane | The component of the nuclear inner membrane consisting of gene products and protein complexes that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Secondary plasmodesma | |
| Type I site-specific deoxyribonuclease complex | |
| Actin filament bundle of filopodium | |
| Intrinsic component of plastid outer membrane | |
| Intrinsic component of chloroplast outer membrane | |
| Interferon regulatory factor 3 complex | An interferon regulatory factor complex that consists of a homodimer of interferon regulatory factor 3. |
| Pip2-Oaf1 complex | |
| Cellular bud tip | The end of a cellular bud distal to the site of attachment to the mother cell. |
| Endosome to plasma membrane transport vesicle | |
| DNA-dependent protein kinase-DNA ligase 4 complex | A large protein complex which is involved in the repair of DNA double-strand breaks and, in mammals, V(D)J recombination events. It consists of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), the DNA end-binding heterodimer Ku, the nuclear phosphoprotein XRCC4 or a homolog thereof, and DNA ligase IV. |
| ficolin-1-rich granule lumen | |
| Inner membrane pellicle complex | |
| BID-BCL-xl complex | |
| Smooth endoplasmic reticulum membrane | The lipid bilayer surrounding the smooth endoplasmic reticulum. |
| IgY immunoglobulin complex | A protein complex composed of two identical immunoglobulin heavy chains of the IgY isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgY immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph. |
| Plasma membrane proton-transporting ATP synthase complex, catalytic core F(1) | |
| Lamellipodium membrane | The portion of the plasma membrane surrounding a lamellipodium. |
| Chromoplast stroma | |
| Cytoplasmic origin of replication recognition complex | A multisubunit complex that is located at the replication origins of a chromosome in the cytoplasm. |
| Chloroplast photosystem II | An integral chloroplast membrane complex containing the P680 reaction center. In the light, PSII functions as a water-plastoquinone oxidoreductase, transferring electrons from water to plastoquinone. |
| SCF-Ucc1 ubiquitin ligase complex | |
| Plastid pyruvate dehydrogenase complex | Complex that carries out the oxidative decarboxylation of pyruvate to form acetyl-CoA; comprises subunits possessing three catalytic activities: pyruvate dehydrogenase (E1), dihydrolipoamide S-acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). This complex is found in plant plastids and is distinct from the one found in mitochondria. |
| Specific granule membrane | The lipid bilayer surrounding a specific granule, a granule with a membranous, tubular internal structure, found primarily in mature neutrophil cells. Most are released into the extracellular fluid. Specific granules contain lactoferrin, lysozyme, vitamin B12 binding protein and elastase. |
| Mannosome | A specialised tubular organelle, assembled in hexagonal bundles within an external membrane. Mannosomes are specific to molluscs and are thought to be involved in a general stress reaction. |
| Endoplasmic reticulum-vacuole membrane contact site | |
| Aim21-Tda2 complex | |
| Extraorganismal space | The environmental space outside of an organism; this may be a host organism in the case of parasitic and symbiotic organisms. |
| Platelet alpha granule lumen | The volume enclosed by the membrane of the platelet alpha granule. |
| Other organism cell membrane | The cell membrane of a secondary organism with which the first organism is interacting. |
| proton-transporting ATP synthase complex, catalytic core F(1) | The sector of a hydrogen-transporting ATP synthase complex in which the catalytic activity resides; it comprises the catalytic core and central stalk, and is peripherally associated with a membrane, such as the plasma membrane or the mitochondrial inner membrane, when the entire ATP synthase is assembled. |
| Mannan polymerase II complex | |
| Azurophil granule lumen | The volume enclosed by the membrane of an azurophil granule, a primary lysosomal granule found in neutrophil granulocytes that contains a wide range of hydrolytic enzymes and is released into the extracellular fluid. |
| Intrinsic component of nuclear inner membrane | The component of the nuclear inner membrane consisting of gene products and protein complexes that have some covalently attached part (e.g. peptide sequence or GPI anchor), which spans or is embedded in one or both leaflets of the membrane. |
| Actin fusion focus | |
| Intrinsic component of synaptic membrane | |
| Collagen type VII anchoring fibril | |
| Filopodium membrane | The portion of the plasma membrane surrounding a filopodium. |
| Phosphatidylinositol transporter complex | |
| Hexameric IgM immunoglobulin complex | A circulating form of IgM consisting of a hexamer of IgM core units with a single J chain polypeptide. |
| Collagen type IX trimer | A collagen heterotrimer containing type IX alpha chains in alpha1(IX)alpha2(IX)alpha3(IX) trimers; type IX collagen triple helices associate to form a structure that links glycosaminoglycans to type II collagen fibrils. |
| Collagen type II trimer | A collagen homotrimer of alpha1(II) chains; type II collagen triple helices associate to form fibrils. |
| gamma-catenin-TCF7L2 complex | A protein complex that contains gamma-catenin and TCF7L2 (TCF4), binds to the TCF DNA motif within a promoter element, and is involved in the regulation of WNT target gene transcription. |
| interleukin-12-interleukin-12 receptor complex | |
| Viral assembly intermediate | Specific locations and structures in the virus infected cell involved in assembling new virions. |
| alphaIIb-beta3 integrin-CD9 complex | A protein complex that consists of an alphaIIb-beta3 integrin complex bound to the cell surface protein CD9. |
| ficolin-1-rich granule membrane | |
| Intrinsic component of plastid membrane | |
| PUMA-BCL-2 complex | |
| Integral component of synaptic membrane | |
| Integral component of presynaptic membrane | |
| Counting factor complex | |
| SOD1-calcineurin complex | |
| Phenyloplast | |
| Polytene chromosome puff | A swelling at a site along the length of a polytene chromosome, thought to be the site of active transcription. |
| Plastid mRNA editing complex | |
| Autophagosome lumen | |
| Slime layer | A slime layer is an easily removed, diffuse, unorganized layer of extracellular material that surrounds a cell. Specifically this consists mostly of exopolysaccharides, glycoproteins, and glycolipids. |
| mitochondrion-associated adherens complex | |
| Heteromeric SMAD protein complex | |
| Cellular bud scar | |
| SHREC2 complex | |
| Mitochondrial inner-outer membrane contact site | |
| classical-complement-pathway C3/C5 convertase complex | |
| Apicolateral plasma membrane | The apical end of the lateral plasma membrane of epithelial cells. |
| Presynaptic active zone dense projection | |
| Pirellulosome | |
| Dendritic cell dendrite | |
| SCF-Mdm30 ubiquitin ligase complex | |
| Intrinsic component of presynaptic membrane | |
| clathrin-sculpted gamma-aminobutyric acid transport vesicle membrane | The lipid bilayer surrounding a clathrin-sculpted gamma-aminobutyric acid transport vesicle. |
| Primary endosperm nucleus | Nucleus resulting from the fusion of the male gamete and two polar nuclei in the central cell of the embryo sac. |
| Plasmodesmatal plasma membrane | |
| Collagen type III trimer | A collagen homotrimer of alpha1(III) chains; type III collagen triple helices associate to form fibrils. |
| Cytoplasmic side of dendritic spine plasma membrane | |
| Multivesicular body lumen | |
| Multivesicular body, internal vesicle lumen | The volume enclosed by the membrane of the multivesicular body internal vesicle. |
| Cnida | |
| alpha6-beta4 integrin-laminin 5 complex | A protein complex that consists of an alpha6-beta4 integrin complex bound to laminin 5. |
| alphav-beta1 integrin-osteopontin complex | A protein complex that consists of an alphav-beta1 integrin complex bound to osteopontin. |
| Prominosome | An extracellular membrane-bounded vesicle that contains prominin proteins (in mouse Prom1/CD33 or Prom2) and are found in body fluids including ventricular fluid, saliva, urine and seminal fluid. In the ventricular fluid of the developing mouse brain two major classes of these particles have been observed (P2 particles of 500-1000 nm and P4 particles of 50-80 nm) which likely originate from microvilli, primary cilia and/or the midbody of neuroepithelial cells. The physiological role is not known. |
| NOXA-BCL-xl complex | |
| Spine apparatus membrane | |
| Integral component of lumenal side of endoplasmic reticulum membrane | The component of the endoplasmic reticulum membrane consisting of the gene products that penetrate only the lumenal side of the membrane. |
| Lignin network | |
| Leaf papilla | |
| Multivesicular body, internal vesicle | A membrane-bounded vesicle wholly contained within a multivesicular body. |
| Macropinocytic cup membrane | |
| ATF1-ATF4 transcription factor complex | |
| Proteasome core complex, alpha-subunit complex | The proteasome core subcomplex that constitutes the two outer rings of the proteasome core complex. An example of this component is found in Mus musculus. |
| alphav-beta3 integrin-CD47 complex | A protein complex that consists of an alphav-beta3 integrin complex bound to CD47 (also known as IAP). |
| Presynaptic endosome membrane | |
| Platelet dense granule lumen | |
| BID-BCL-2 complex | A heterodimeric protein complex consisting of BID and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators. |
| Actin tubule | |
| Tec1p-Ste12p-Dig1p complex | |
| Reservosome membrane | |
| Chitosome membrane | |
| Hyaline layer | A multilayered extraembryonic matrix that functions as a substrate for cell adhesion through early development. It is thought to protect and lubricate the embryo, stabilize the blastomeres during morphogenesis, and regulate nutrient intake. The major constituent of the hyaline layer is the protein hyalin. This matrix has been found in echinoderms. |
| Plasma membrane of cell tip | |
| Smooth endoplasmic reticulum lumen | The volume enclosed by the membranes of the smooth endoplasmic reticulum. |
| Integral component of mitochondrial outer membrane | The component of the mitochondrial outer membrane consisting of the gene products that have some part that penetrates at least one leaflet of the membrane bilayer. This component includes gene products that are buried in the bilayer with no exposure outside the bilayer. |
| Postsynaptic endosome | |
| Endexine | |
| Somatic ring canal | |
| Organellar chromatophore | |
| Terminal cisterna lumen | The region between the inner and outer lipid bilayers of the terminal cisterna envelope. This space is enriched in calsequestrin. |
| Free sarcoplasmic reticulum membrane | |
| mating-type region heterochromatin | |
| alphav-beta5 integrin-vitronectin complex | |
| NOS2-CD74 complex | A protein complex comprising nitric oxide synthase 2 and CD74. This stable complex formation is thought to prevent CD74 degradation by caspases. |
| Lewy body core | The center portion of a Lewy body. In Parkinson's disease, it contains a matted meshwork of filaments. |
| Autolysosome lumen | |
| Scrib-APC-beta-catenin complex | A protein complex that contains the Scribble protein (a cell polarity determinant), the tumor suppressor protein adenomatous polyposis coli (APC), and beta-catenin; may be involved in the control of cell proliferation. |
| Cytoplasmic side of endoplasmic reticulum membrane | The side (leaflet) of the plasma membrane that faces the cytoplasm. |
| IgG immunoglobulin complex, circulating | |
| Ecdysone receptor holocomplex | |
| Prospore membrane leading edge | |
| Bursicon neuropeptide hormone complex | |
| FACIT collagen trimer | A collagen trimer that associates with collagen fibrils and consists of collagen monomers that contain two or more relatively short triple-helical domains connected by non-triple-helical sequences. |
| fibronectin-tissue transglutaminase complex | A protein complex that consists of fibronectin bound to tissue transglutaminase, and is involved in cell adhesion. |
| U2-type post-mRNA release spliceosomal complex | A spliceosomal complex that is formed following the release of the spliced product from the post-spliceosomal complex and contains the excised intron and the U2, U5 and U6 snRNPs. |
| Extrinsic component of synaptic membrane | |
| Extrinsic component of postsynaptic membrane | |
| BRCA2-MAGE-D1 complex | A heterodimeric protein complex formed of BRCA2 and MAGE-D1; may mediate the synergistic activities of the two proteins in regulating cell growth. |
| PUMA-BCL-xl complex | |
| MdtBC Complex | |
| Hda-beta clamp complex | |
| IgM immunoglobulin complex, circulating | A polymer of five or six IgM core units each composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains, held together by disulfide bonds; the individual IgM core units are held together via disulfide bonds with a single J chain polypeptide acting as a bridge between two of the polymeric units. Circulating IgM is present in the extracellular space, in mucosal areas or other tissues, or in the blood or lymph. |
| IgD immunoglobulin complex, GPI-anchored | |
| alphav-beta3 integrin-vitronectin complex | A protein complex that consists of an alphav-beta3 integrin complex bound to vitronectin. |
| Cytoplasmic side of rough endoplasmic reticulum membrane | |
| alpha3-beta1 integrin-thrombospondin complex | A protein complex that consists of an alpha3-beta1 integrin complex bound to thrombospondin. |
| Right caudal flagellum | |
| Deep fiber | Inward projections of the cytoskeletal structures of the oral apparatus, which form a fiber that extends past the cytostome into the cytoplasm. |
| Gemmule | Spine-like process found on some neurons, e.g., periglomerular cells of olfactory cortex. |
| Phragmosome | A flattened membranous vesicle containing cell wall components. |
| Invertasome | A complex formed by a recombinase, a regulatory protein, and the DNA sequences bound by each protein; catalyzes a reversible site-specific recombination reaction that results in the alternate expression of one or more genes in various contexts. |
| Dendritic spine cytoplasm | |
| clathrin-sculpted glutamate transport vesicle membrane | The lipid bilayer surrounding a clathrin-sculpted glutamate transport vesicle. |
| Endoplasmic reticulum tubular network membrane | |
| Rough endoplasmic reticulum cisterna | |
| post-anaphase array microtubule | |
| clathrin-sculpted glutamate transport vesicle | A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release and containing glutamate. |
| Dendritic spine origin | |
| Extrinsic component of thylakoid membrane | |
| Mitotic spindle polar microtubule | |
| Lateral cortical node | |
| Synaptobrevin 2-SNAP-25-syntaxin-1a-complexin II complex | A SNARE complex that contains synaptobrevin 2 (VAMP2), SNAP-25, syntaxin 1a, and complexin II (or orthologs thereof). |
| Lytic vacuole within protein storage vacuole | |
| Perforant pathway to dendrate granule cell synapse | |
| Collagen type XIII trimer | A collagen homotrimer of alpha1(XIII) chains; type XIII collagen triple helices span the plasma membrane. |
| clathrin-sculpted monoamine transport vesicle | A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release and containing monoamines. |
| Mitotic actomyosin contractile ring, intermediate layer | |
| clathrin-sculpted monoamine transport vesicle membrane | The lipid bilayer surrounding a clathrin-sculpted monoamine transport vesicle. |
| bacterial-type flagellum basal body, distal rod, L ring | |
| bacterial-type flagellum basal body, distal rod |
