InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: P4HB

Summary

InnateDB Protein

IDBP-72657.6

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

P4HB

Protein Name

prolyl 4-hydroxylase, beta polypeptide

Synonyms

DSI; ERBA2L; GIT; P4Hbeta; PDI; PDIA1; PHDB; PO4DB; PO4HB; PROHB;

Species

Homo sapiens

Ensembl Protein

ENSP00000327801

InnateDB Gene

IDBG-72655 (P4HB)

Protein Structure

UniProt Annotation

Function

This multifunctional protein catalyzes the formation, breakage and rearrangement of disulfide bonds. At the cell surface, seems to act as a reductase that cleaves disulfide bonds of proteins attached to the cell. May therefore cause structural modifications of exofacial proteins. Inside the cell, seems to form/rearrange disulfide bonds of nascent proteins. At high concentrations, functions as a chaperone that inhibits aggregation of misfolded proteins. At low concentrations, facilitates aggregation (anti-chaperone activity). May be involved with other chaperones in the structural modification of the TG precursor in hormone biogenesis. Also acts a structural subunit of various enzymes such as prolyl 4-hydroxylase and microsomal triacylglycerol transfer protein MTTP. {ECO:0000269PubMed:10636893, ECO:0000269PubMed:12485997}.

Subcellular Localization

Endoplasmic reticulum lumen. Melanosome. Cell membrane {ECO:0000305}; Peripheral membrane protein {ECO:0000305}. Note=Highly abundant. In some cell types, seems to be also secreted or associated with the plasma membrane, where it undergoes constant shedding and replacement from intracellular sources (Probable). Localizes near CD4-enriched regions on lymphoid cell surfaces. Identified by mass spectrometry in melanosome fractions from stage I to stage IV. {ECO:0000305}.

Disease Associations

Tissue Specificity

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 89 experimentally validated interaction(s) in this database.
They are also associated with 4 interaction(s) predicted by orthology.

Experimentally validated
Total	89 [view]
Protein-Protein	89 [view]
Protein-DNA	0
Protein-RNA	0
DNA-DNA	0
RNA-RNA	0
DNA-RNA	0

Predicted by orthology
Total	4 [view]

Gene Ontology

Molecular Function

Accession	GO Term
GO:0003756	protein disulfide isomerase activity
GO:0004656	procollagen-proline 4-dioxygenase activity
GO:0005515	protein binding
GO:0016853	isomerase activity
GO:0019899	enzyme binding
GO:0044822	poly(A) RNA binding
GO:0046982	protein heterodimerization activity

Biological Process

GO:0006457	protein folding
GO:0018401	peptidyl-proline hydroxylation to 4-hydroxy-L-proline
GO:0030198	extracellular matrix organization
GO:0034976	response to endoplasmic reticulum stress
GO:0042157	lipoprotein metabolic process
GO:0044281	small molecule metabolic process
GO:0045454	cell redox homeostasis
GO:0071456	cellular response to hypoxia
GO:1902175	regulation of oxidative stress-induced intrinsic apoptotic signaling pathway

Cellular Component

GO:0005576	extracellular region
GO:0005783	endoplasmic reticulum
GO:0005788	endoplasmic reticulum lumen
GO:0005793	endoplasmic reticulum-Golgi intermediate compartment
GO:0005886	plasma membrane
GO:0016222	procollagen-proline 4-dioxygenase complex
GO:0042470	melanosome
GO:0070062	extracellular vesicular exosome