ERP44 Gene

HGNC Family	Protein disulfide isomerases (PDI)
Name	endoplasmic reticulum protein 44
Description	This gene encodes a member of the protein disulfide isomerase (PDI) family of endoplasmic reticulum (ER) proteins. It has an inferred N-terminal signal peptide, a catalytically active thioredoxin (TRX) domain, two TRX-like domains and a C-terminal ER-retention sequence. This protein functions as a pH-regulated chaperone of the secretory pathway and likely plays a role in protein quality control at the endoplasmic reticulum - Golgi interface. [provided by RefSeq, Dec 2016]
Summary	{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n ERp44 is a versatile, endoplasmic reticulum–resident chaperone that plays a central role in ensuring the fidelity of secreted proteins by monitoring their oxidative folding and assembly. Acting through a conserved CRFS motif, ERp44 forms reversible (mixed) disulfide bonds with substrates to mediate thiol‐dependent quality control in the early secretory pathway.\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In adipocytes, ERp44 binds directly to adiponectin—via a critical cysteine residue—to regulate its assembly into high‐molecular‐weight complexes that are essential for proper insulin sensitization and metabolic homeostasis."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "3"}]}, {"type": "t", "text": " Similarly, in B‐lymphocytes, ERp44 participates in immunoglobulin M quality control by interacting with nascent IgM subunits to promote their correct polymerization and assembly."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In addition, ERp44 contributes to the maintenance of ER redox homeostasis by retaining oxidoreductases such as Ero1α, thereby preventing their leakage and fine‐tuning the oxidative folding environment."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "5"}]}, {"type": "t", "text": " Structural and biochemical studies have revealed that ERp44’s activity is governed by pH‐dependent conformational changes—in which its flexible C‐terminal tail (and key histidine residues) occludes or reveals both its substrate–binding site and its RDEL retrieval motif in the Golgi—thus ensuring that mis‐assembled or incompletely oxidized proteins are retrieved back to the ER for further processing."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "6", "end_ref": "8"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Beyond its roles in metabolic and immunologic processes, ERp44 also regulates the intracellular trafficking of other secretory proteins. For instance, it mediates the ER retention of formylglycine‐generating enzyme—a critical factor for sulfatase activation—and controls the cell‐surface expression of the serotonin transporter in trophoblasts, thereby influencing diverse physiological contexts."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "9", "end_ref": "11"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Collectively, these findings underscore that ERp44 is a pivotal regulator of protein quality control and redox homeostasis in the secretory pathway. By dynamically interacting with a range of client proteins, ERp44 ensures that only properly folded and assembled proteins progress along the secretory route—a mechanism that has significant implications for metabolic regulation, immune function, and cellular homeostasis.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Arunkumar E Achari, Sushil K Jain "}, {"type": "b", "children": [{"type": "t", "text": "Adiponectin, a Therapeutic Target for Obesity, Diabetes, and Endothelial Dysfunction."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Int J Mol Sci (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.3390/ijms18061321"}], "href": "https://doi.org/10.3390/ijms18061321"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "28635626"}], "href": "https://pubmed.ncbi.nlm.nih.gov/28635626"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Zhao V Wang, Todd D Schraw, Ja-Young Kim, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Secretion of the adipocyte-specific secretory protein adiponectin critically depends on thiol-mediated protein retention."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell Biol (2007)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1128/MCB.00931-06"}], "href": "https://doi.org/10.1128/MCB.00931-06"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "17353260"}], "href": "https://pubmed.ncbi.nlm.nih.gov/17353260"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Haibo Sha, Liu Yang, Meilian Liu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Adipocyte spliced form of X-box-binding protein 1 promotes adiponectin multimerization and systemic glucose homeostasis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Diabetes (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.2337/db13-1067"}], "href": "https://doi.org/10.2337/db13-1067"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24241534"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24241534"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Tiziana Anelli, Stefania Ceppi, Leda Bergamelli, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Sequential steps and checkpoints in the early exocytic compartment during secretory IgM biogenesis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "EMBO J (2007)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/sj.emboj.7601844"}], "href": "https://doi.org/10.1038/sj.emboj.7601844"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "17805346"}], "href": "https://pubmed.ncbi.nlm.nih.gov/17805346"}]}, {"type": "r", "ref": 5, "children": [{"type": "t", "text": "Mieko Otsu, Gloria Bertoli, Claudio Fagioli, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Dynamic retention of Ero1alpha and Ero1beta in the endoplasmic reticulum by interactions with PDI and ERp44."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Antioxid Redox Signal (2006)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1089/ars.2006.8.274"}], "href": "https://doi.org/10.1089/ars.2006.8.274"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "16677073"}], "href": "https://pubmed.ncbi.nlm.nih.gov/16677073"}]}, {"type": "r", "ref": 6, "children": [{"type": "t", "text": "Stefano Vavassori, Margherita Cortini, Shoji Masui, et al. "}, {"type": "b", "children": [{"type": "t", "text": "A pH-regulated quality control cycle for surveillance of secretory protein assembly."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell (2013)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.molcel.2013.04.016"}], "href": "https://doi.org/10.1016/j.molcel.2013.04.016"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "23685074"}], "href": "https://pubmed.ncbi.nlm.nih.gov/23685074"}]}, {"type": "r", "ref": 7, "children": [{"type": "t", "text": "Sara Sannino, Tiziana Anelli, Margherita Cortini, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Progressive quality control of secretory proteins in the early secretory compartment by ERp44."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Cell Sci (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1242/jcs.153239"}], "href": "https://doi.org/10.1242/jcs.153239"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25097228"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25097228"}]}, {"type": "r", "ref": 8, "children": [{"type": "t", "text": "Kai Yang, De-Feng Li, Xi'e Wang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Crystal Structure of the ERp44-Peroxiredoxin 4 Complex Reveals the Molecular Mechanisms of Thiol-Mediated Protein Retention."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Structure (2016)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.str.2016.08.002"}], "href": "https://doi.org/10.1016/j.str.2016.08.002"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "27642162"}], "href": "https://pubmed.ncbi.nlm.nih.gov/27642162"}]}, {"type": "r", "ref": 9, "children": [{"type": "t", "text": "Malaiyalam Mariappan, Karthikeyan Radhakrishnan, Thomas Dierks, et al. "}, {"type": "b", "children": [{"type": "t", "text": "ERp44 mediates a thiol-independent retention of formylglycine-generating enzyme in the endoplasmic reticulum."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2008)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M709171200"}], "href": "https://doi.org/10.1074/jbc.M709171200"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "18178549"}], "href": "https://pubmed.ncbi.nlm.nih.gov/18178549"}]}, {"type": "r", "ref": 10, "children": [{"type": "t", "text": "Yicong Li, Coedy Hadden, Preeti Singh, et al. "}, {"type": "b", "children": [{"type": "t", "text": "GDM-associated insulin deficiency hinders the dissociation of SERT from ERp44 and down-regulates placental 5-HT uptake."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Proc Natl Acad Sci U S A (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1073/pnas.1416675112"}], "href": "https://doi.org/10.1073/pnas.1416675112"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25512553"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25512553"}]}, {"type": "r", "ref": 11, "children": [{"type": "t", "text": "Y Zou, Z Jiang, X Yu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "MiR-101 regulates apoptosis of trophoblast HTR-8/SVneo cells by targeting endoplasmic reticulum (ER) protein 44 during preeclampsia."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Hum Hypertens (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/jhh.2014.35"}], "href": "https://doi.org/10.1038/jhh.2014.35"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24804790"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24804790"}]}]}]}
Synonyms	PDIA10, TXNDC4
Proteins	ERP44_HUMAN
NCBI Gene ID	23071
API
Download Associations
Predicted Functions
Co-expressed Genes
Expression in Tissues and Cell Lines

Functional Associations

ERP44 has 7,185 functional associations with biological entities spanning 8 categories (molecular profile, organism, chemical, functional term, phrase or reference, disease, phenotype or trait, structural feature, cell line, cell type or tissue, gene, protein or microRNA) extracted from 116 datasets.

Click the + buttons to view associations for ERP44 from the datasets below.

If available, associations are ranked by standardized value

Harmonizome 3.0

ERP44 Gene

Functional Associations

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

	Dataset	Summary
	Achilles Cell Line Gene Essentiality Profiles	cell lines with fitness changed by ERP44 gene knockdown relative to other cell lines from the Achilles Cell Line Gene Essentiality Profiles dataset.
	Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of ERP44 gene relative to other tissues from the Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles dataset.
	Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles	tissues with high or low expression of ERP44 gene relative to other tissues from the Allen Brain Atlas Adult Mouse 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 ERP44 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 ERP44 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 ERP44 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 ERP44 gene relative to other tissues from the Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles dataset.
	BioGPS Cell Line Gene Expression Profiles	cell lines with high or low expression of ERP44 gene relative to other cell lines from the BioGPS Cell Line Gene Expression Profiles dataset.
	BioGPS Human Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of ERP44 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 ERP44 gene relative to other cell types and tissues from the BioGPS Mouse Cell Type and Tissue Gene Expression Profiles dataset.
	Carcinogenome Chemical Perturbation Carcinogenicity Signatures	small molecule perturbations changing expression of ERP44 gene from the Carcinogenome Chemical Perturbation Carcinogenicity Signatures dataset.
	CCLE Cell Line Gene CNV Profiles	cell lines with high or low copy number of ERP44 gene relative to other cell lines from the CCLE Cell Line Gene CNV Profiles dataset.
	CCLE Cell Line Gene Expression Profiles	cell lines with high or low expression of ERP44 gene relative to other cell lines from the CCLE Cell Line Gene Expression Profiles dataset.
	CCLE Cell Line Proteomics	Cell lines associated with ERP44 protein from the CCLE Cell Line Proteomics dataset.
	CellMarker Gene-Cell Type Associations	cell types associated with ERP44 gene from the CellMarker Gene-Cell Type Associations dataset.
	ChEA Transcription Factor Binding Site Profiles	transcription factor binding site profiles with transcription factor binding evidence at the promoter of ERP44 gene from the CHEA Transcription Factor Binding Site Profiles dataset.
	ChEA Transcription Factor Targets	transcription factors binding the promoter of ERP44 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 ERP44 gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets 2022 dataset.
	CMAP Signatures of Differentially Expressed Genes for Small Molecules	small molecule perturbations changing expression of ERP44 gene from the CMAP Signatures of Differentially Expressed Genes for Small Molecules dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores	cellular components containing ERP44 protein from the COMPARTMENTS Curated Protein Localization Evidence Scores dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores 2025	cellular components containing ERP44 protein from the COMPARTMENTS Curated Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores	cellular components co-occuring with ERP44 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 ERP44 protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset.
	COSMIC Cell Line Gene CNV Profiles	cell lines with high or low copy number of ERP44 gene relative to other cell lines from the COSMIC Cell Line Gene CNV Profiles dataset.
	COSMIC Cell Line Gene Mutation Profiles	cell lines with ERP44 gene mutations from the COSMIC Cell Line Gene Mutation Profiles dataset.
	CTD Gene-Chemical Interactions	chemicals interacting with ERP44 gene/protein from the curated CTD Gene-Chemical Interactions dataset.
	CTD Gene-Disease Associations	diseases associated with ERP44 gene/protein from the curated CTD Gene-Disease Associations dataset.
	dbGAP Gene-Trait Associations	traits associated with ERP44 gene in GWAS and other genetic association datasets from the dbGAP Gene-Trait Associations dataset.
	DeepCoverMOA Drug Mechanisms of Action	small molecule perturbations with high or low expression of ERP44 protein relative to other small molecule perturbations from the DeepCoverMOA Drug Mechanisms of Action dataset.
	DepMap CRISPR Gene Dependency	cell lines with fitness changed by ERP44 gene knockdown relative to other cell lines from the DepMap CRISPR Gene Dependency dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores	diseases co-occuring with ERP44 gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores 2025	diseases co-occuring with ERP44 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 ERP44 gene in GWAS and other genetic association datasets from the DisGeNET Gene-Disease Associations dataset.
	ENCODE Histone Modification Site Profiles	histone modification site profiles with high histone modification abundance at ERP44 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 ERP44 gene from the ENCODE Transcription Factor Binding Site Profiles dataset.
	ENCODE Transcription Factor Targets	transcription factors binding the promoter of ERP44 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 ERP44 from the ESCAPE Omics Signatures of Genes and Proteins for Stem Cells dataset.
	GDSC Cell Line Gene Expression Profiles	cell lines with high or low expression of ERP44 gene relative to other cell lines from the GDSC Cell Line Gene Expression Profiles dataset.
	GeneRIF Biological Term Annotations	biological terms co-occuring with ERP44 gene in literature-supported statements describing functions of genes from the GeneRIF Biological Term Annotations dataset.
	GeneSigDB Published Gene Signatures	PubMedIDs of publications reporting gene signatures containing ERP44 from the GeneSigDB Published Gene Signatures dataset.