STT3B Gene

HGNC Family	Glycosyltransferases, Oligosaccharyltransferase complex
Name	STT3B, subunit of the oligosaccharyltransferase complex (catalytic)
Description	The protein encoded by this gene is a catalytic subunit of a protein complex that transfers oligosaccharides onto asparagine residues. Defects in this gene are a cause of congenital disorder of glycosylation Ix (CDG1X). [provided by RefSeq, Jun 2014]
Summary	{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nThe oligosaccharyltransferase (OST) enzyme complex in metazoans exists in two main isoforms that differ in their catalytic subunits. One isoform contains STT3A, which is predominantly responsible for cotranslational modification of nascent polypeptides, whereas STT3B plays a complementary role by modifying glycosylation acceptor sites that are skipped during cotranslational scanning. In particular, STT3B efficiently transfers N‐glycans onto sites in close proximity to the N‐terminal signal peptide and on extreme C‐terminal regions that emerge only after translation is complete. This division of labor helps maximize overall glycosylation efficiency and is underlined by the findings that distinct OST complexes harboring STT3B contribute to tissue-specific glycan heterogeneity and regulate enzymatic properties in response to glycoprotein flux."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "4"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nDetailed mechanistic studies have revealed that STT3B’s enzymatic activity is highly sensitive to the context of the acceptor sequon. The efficiency of posttranslational glycosylation by STT3B is influenced by the nature of the amino acid residing in the “X” position of the N‑X‑T/S motif, with NXT sequons generally being more favorable than NXS sites. Under conditions where normally cryptic glycosylation sites become exposed (for example, in unfolded or misfolded proteins), STT3B catalyzes glycosylation events that can act as a molecular tag for quality control and subsequent endoplasmic reticulum–associated degradation. Moreover, STT3B is unique in its ability to hydrolyze lipid‐linked oligosaccharides (LLOs) when acceptor occupancy is low—a function that appears to be modulated by the presence of cofactors, highlighting a “moonlighting” capability in LLO processing."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "5", "end_ref": "8"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nBeyond its classical role in glycoprotein biogenesis, STT3B has important implications in human disease and pathogen interactions. Mutations in the STT3B gene are causative for a congenital disorder of glycosylation that manifests with neurologic abnormalities and growth defects, emphasizing its critical role in protein modification. In viral infections such as dengue, STT3B is instrumental in stabilizing associated factors, like the oxidoreductase MAGT1, which in turn facilitates viral replication. Furthermore, in the setting of certain cancers, STT3B-mediated glycosylation of key regulators—exemplified by its modification of epiregulin at a distinct N‑glycosylation site—has been shown to affect the stability and cellular localization of factors that drive immune evasion. Proteomic analyses also indicate that loss of STT3B results in subtle yet significant alterations in glycan profiles and protein expression, further underscoring its regulatory influence in diverse biological contexts."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "9", "end_ref": "12"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Daniel J Kelleher, Denise Karaoglu, Elisabet C Mandon, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Oligosaccharyltransferase isoforms that contain different catalytic STT3 subunits have distinct enzymatic properties."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell (2003)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/s1097-2765(03)00243-0"}], "href": "https://doi.org/10.1016/s1097-2765(03"}, {"type": "t", "text": "00243-0) PMID: "}, {"type": "a", "children": [{"type": "t", "text": "12887896"}], "href": "https://pubmed.ncbi.nlm.nih.gov/12887896"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Catalina Ruiz-Canada, Daniel J Kelleher, Reid Gilmore "}, {"type": "b", "children": [{"type": "t", "text": "Cotranslational and posttranslational N-glycosylation of polypeptides by distinct mammalian OST isoforms."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cell (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.cell.2008.11.047"}], "href": "https://doi.org/10.1016/j.cell.2008.11.047"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19167329"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19167329"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Shiteshu Shrimal, Steven F Trueman, Reid Gilmore "}, {"type": "b", "children": [{"type": "t", "text": "Extreme C-terminal sites are posttranslocationally glycosylated by the STT3B isoform of the OST."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Cell Biol (2013)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1083/jcb.201301031"}], "href": "https://doi.org/10.1083/jcb.201301031"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "23530066"}], "href": "https://pubmed.ncbi.nlm.nih.gov/23530066"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Toshihiko Kitajima, Wei Xue, Yi-Shi Liu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Construction of green fluorescence protein mutant to monitor STT3B-dependent N-glycosylation."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "FEBS J (2018)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1111/febs.14375"}], "href": "https://doi.org/10.1111/febs.14375"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "29282902"}], "href": "https://pubmed.ncbi.nlm.nih.gov/29282902"}]}, {"type": "r", "ref": 5, "children": [{"type": "t", "text": "Takashi Sato, Yasuhiro Sako, Misato Sho, et al. "}, {"type": "b", "children": [{"type": "t", "text": "STT3B-dependent posttranslational N-glycosylation as a surveillance system for secretory protein."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell (2012)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.molcel.2012.04.015"}], "href": "https://doi.org/10.1016/j.molcel.2012.04.015"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "22607976"}], "href": "https://pubmed.ncbi.nlm.nih.gov/22607976"}]}, {"type": "r", "ref": 6, "children": [{"type": "t", "text": "Heidi L H Malaby, William R Kobertz "}, {"type": "b", "children": [{"type": "t", "text": "The middle X residue influences cotranslational N-glycosylation consensus site skipping."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Biochemistry (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1021/bi500681p"}], "href": "https://doi.org/10.1021/bi500681p"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25029371"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25029371"}]}, {"type": "r", "ref": 7, "children": [{"type": "t", "text": "Hua Lu, Charles S Fermaintt, Natalia A Cherepanova, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Mammalian STT3A/B oligosaccharyltransferases segregate N-glycosylation at the translocon from lipid-linked oligosaccharide hydrolysis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Proc Natl Acad Sci U S A (2018)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1073/pnas.1806034115"}], "href": "https://doi.org/10.1073/pnas.1806034115"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "30181269"}], "href": "https://pubmed.ncbi.nlm.nih.gov/30181269"}]}, {"type": "r", "ref": 8, "children": [{"type": "t", "text": "Natalia A Cherepanova, Sergey V Venev, John D Leszyk, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Quantitative glycoproteomics reveals new classes of STT3A- and STT3B-dependent N-glycosylation sites."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Cell Biol (2019)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1083/jcb.201904004"}], "href": "https://doi.org/10.1083/jcb.201904004"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "31296534"}], "href": "https://pubmed.ncbi.nlm.nih.gov/31296534"}]}, {"type": "r", "ref": 9, "children": [{"type": "t", "text": "Shiteshu Shrimal, Bobby G Ng, Marie-Estelle Losfeld, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Mutations in STT3A and STT3B cause two congenital disorders of glycosylation."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Hum Mol Genet (2013)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1093/hmg/ddt312"}], "href": "https://doi.org/10.1093/hmg/ddt312"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "23842455"}], "href": "https://pubmed.ncbi.nlm.nih.gov/23842455"}]}, {"type": "r", "ref": 10, "children": [{"type": "t", "text": "David L Lin, Natalia A Cherepanova, Leonia Bozzacco, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Dengue Virus Hijacks a Noncanonical Oxidoreductase Function of a Cellular Oligosaccharyltransferase Complex."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "mBio (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1128/mBio.00939-17"}], "href": "https://doi.org/10.1128/mBio.00939-17"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "28720733"}], "href": "https://pubmed.ncbi.nlm.nih.gov/28720733"}]}, {"type": "r", "ref": 11, "children": [{"type": "t", "text": "Piaopiao Wen, Jingru Chen, Chenyang Zuo, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Proteome and Glycoproteome Analyses Reveal the Protein N-Linked Glycosylation Specificity of STT3A and STT3B."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Cells (2022)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.3390/cells11182775"}], "href": "https://doi.org/10.3390/cells11182775"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "36139350"}], "href": "https://pubmed.ncbi.nlm.nih.gov/36139350"}]}, {"type": "r", "ref": 12, "children": [{"type": "t", "text": "Shengming Xu, Haifeng Wang, Yu Zhu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Stabilization of EREG via STT3B-mediated N-glycosylation is critical for PDL1 upregulation and immune evasion in head and neck squamous cell carcinoma."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Int J Oral Sci (2024)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/s41368-024-00311-1"}], "href": "https://doi.org/10.1038/s41368-024-00311-1"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "38945975"}], "href": "https://pubmed.ncbi.nlm.nih.gov/38945975"}]}]}]}
Synonyms	STT3-B, CDG1X
Proteins	STT3B_HUMAN
NCBI Gene ID	201595
API
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Predicted Functions
Co-expressed Genes
Expression in Tissues and Cell Lines

Functional Associations

STT3B has 6,976 functional associations with biological entities spanning 9 categories (molecular profile, organism, disease, phenotype or trait, functional term, phrase or reference, chemical, structural feature, cell line, cell type or tissue, gene, protein or microRNA, sequence feature) extracted from 118 datasets.

Click the + buttons to view associations for STT3B from the datasets below.

If available, associations are ranked by standardized value

Harmonizome 3.0

STT3B Gene

Functional Associations

Please acknowledge the Harmonizome in your publications by citing the following reference(s):

	Dataset	Summary
	Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of STT3B gene relative to other tissues from the Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles dataset.
	Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles	tissue samples with high or low expression of STT3B gene relative to other tissue samples from the Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles dataset.
	Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray	tissue samples with high or low expression of STT3B gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray dataset.
	Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq	tissue samples with high or low expression of STT3B gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq dataset.
	Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of STT3B gene relative to other tissues from the Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles dataset.
	BioGPS Human Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of STT3B gene relative to other cell types and tissues from the BioGPS Human Cell Type and Tissue Gene Expression Profiles dataset.
	BioGPS Mouse Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of STT3B gene relative to other cell types and tissues from the BioGPS Mouse Cell Type and Tissue Gene Expression Profiles dataset.
	CCLE Cell Line Gene CNV Profiles	cell lines with high or low copy number of STT3B gene relative to other cell lines from the CCLE Cell Line Gene CNV Profiles dataset.
	CCLE Cell Line Proteomics	Cell lines associated with STT3B protein from the CCLE Cell Line Proteomics dataset.
	ChEA Transcription Factor Binding Site Profiles	transcription factor binding site profiles with transcription factor binding evidence at the promoter of STT3B gene from the CHEA Transcription Factor Binding Site Profiles dataset.
	ChEA Transcription Factor Targets	transcription factors binding the promoter of STT3B gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets dataset.
	ChEA Transcription Factor Targets 2022	transcription factors binding the promoter of STT3B gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets 2022 dataset.
	ClinVar Gene-Phenotype Associations	phenotypes associated with STT3B gene from the curated ClinVar Gene-Phenotype Associations dataset.
	ClinVar Gene-Phenotype Associations 2025	phenotypes associated with STT3B gene from the curated ClinVar Gene-Phenotype Associations 2025 dataset.
	CM4AI KOLF21J CRISPRi Gene Perturbation Atlas	gene perturbations changing expression of STT3B gene from the CM4AI KOLF21J CRISPRi Gene Perturbation Atlas dataset.
	CM4AI U2OS Cell Map Protein Localization Assemblies	assemblies containing STT3B protein from integrated AP-MS and IF data from the CM4AI U2OS Cell Map Protein Localization Assemblies dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores	cellular components containing STT3B protein from the COMPARTMENTS Curated Protein Localization Evidence Scores dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores 2025	cellular components containing STT3B protein from the COMPARTMENTS Curated Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Experimental Protein Localization Evidence Scores 2025	cellular components containing STT3B protein in low- or high-throughput protein localization assays from the COMPARTMENTS Experimental Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores	cellular components co-occuring with STT3B protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025	cellular components co-occuring with STT3B protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset.
	CORUM Protein Complexes	protein complexs containing STT3B protein from the CORUM Protein Complexes dataset.
	COSMIC Cell Line Gene CNV Profiles	cell lines with high or low copy number of STT3B gene relative to other cell lines from the COSMIC Cell Line Gene CNV Profiles dataset.
	COSMIC Cell Line Gene Mutation Profiles	cell lines with STT3B gene mutations from the COSMIC Cell Line Gene Mutation Profiles dataset.
	CTD Gene-Chemical Interactions	chemicals interacting with STT3B gene/protein from the curated CTD Gene-Chemical Interactions dataset.
	CTD Gene-Disease Associations	diseases associated with STT3B gene/protein from the curated CTD Gene-Disease Associations dataset.
	DepMap CRISPR Gene Dependency	cell lines with fitness changed by STT3B gene knockdown relative to other cell lines from the DepMap CRISPR Gene Dependency dataset.
	DISEASES Curated Gene-Disease Association Evidence Scores	diseases involving STT3B gene from the DISEASES Curated Gene-Disease Assocation Evidence Scores dataset.
	DISEASES Curated Gene-Disease Association Evidence Scores 2025	diseases involving STT3B gene from the DISEASES Curated Gene-Disease Association Evidence Scores 2025 dataset.
	DISEASES Experimental Gene-Disease Association Evidence Scores	diseases associated with STT3B gene in GWAS datasets from the DISEASES Experimental Gene-Disease Assocation Evidence Scores dataset.
	DISEASES Experimental Gene-Disease Association Evidence Scores 2025	diseases associated with STT3B gene in GWAS datasets from the DISEASES Experimental Gene-Disease Assocation Evidence Scores 2025 dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores 2025	diseases co-occuring with STT3B gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores 2025 dataset.
	DisGeNET Gene-Disease Associations	diseases associated with STT3B gene in GWAS and other genetic association datasets from the DisGeNET Gene-Disease Associations dataset.
	DisGeNET Gene-Phenotype Associations	phenotypes associated with STT3B gene in GWAS and other genetic association datasets from the DisGeNET Gene-Phenoptype Associations dataset.
	ENCODE Histone Modification Site Profiles	histone modification site profiles with high histone modification abundance at STT3B gene from the ENCODE Histone Modification Site Profiles dataset.
	ENCODE Transcription Factor Binding Site Profiles	transcription factor binding site profiles with transcription factor binding evidence at the promoter of STT3B gene from the ENCODE Transcription Factor Binding Site Profiles dataset.
	ENCODE Transcription Factor Targets	transcription factors binding the promoter of STT3B gene in ChIP-seq datasets from the ENCODE Transcription Factor Targets dataset.
	ESCAPE Omics Signatures of Genes and Proteins for Stem Cells	PubMedIDs of publications reporting gene signatures containing STT3B from the ESCAPE Omics Signatures of Genes and Proteins for Stem Cells dataset.
	GAD Gene-Disease Associations	diseases associated with STT3B gene in GWAS and other genetic association datasets from the GAD Gene-Disease Associations dataset.
	GeneRIF Biological Term Annotations	biological terms co-occuring with STT3B gene in literature-supported statements describing functions of genes from the GeneRIF Biological Term Annotations dataset.