GRP78 Endoplasmic reticulum chaperone that plays a key role in protein folding and quality control in the endoplasmic reticulum lumen. Involved in the correct folding of proteins and degradation of misfolded proteins via its interaction with DNAJC10/ERdj5, probably to facilitate the release of DNAJC10/ERdj5 from its substrate. Acts as a key repressor of the ERN1/IRE1-mediated unfolded protein response (UPR). In the unstressed endoplasmic reticulum, recruited by DNAJB9/ERdj4 to the luminal region of ERN1/IRE1, leading to disrupt the dimerization of ERN1/IRE1, thereby inactivating ERN1/IRE1. Accumulation of misfolded protein in the endoplasmic reticulum causes release of HSPA5/BiP from ERN1/IRE1, allowing homodimerization and subsequent activation of ERN1/IRE1. Plays an auxiliary role in post-translational transport of small presecretory proteins across endoplasmic reticulum (ER). May function as an allosteric modulator for SEC61 channel-forming translocon complex, likely cooperating with SEC62 to enable the productive insertion of these precursors into SEC61 channel. Appears to specifically regulate translocation of precursors having inhibitory residues in their mature region that weaken channel gating. Belongs to the heat shock protein 70 family. Note: This description may include information from UniProtKB.
Protein type: Chaperone; Heat shock protein
Chromosomal Location of Human Ortholog: 2 B|2 22.94 cM
Cellular Component:  cell surface; cytoplasm; cytosol; endoplasmic reticulum; endoplasmic reticulum chaperone complex; endoplasmic reticulum lumen; endoplasmic reticulum membrane; endoplasmic reticulum-Golgi intermediate compartment; integral component of endoplasmic reticulum membrane; intracellular membrane-bounded organelle; membrane; midbody; mitochondrion; nucleus; plasma membrane; protein-containing complex; smooth endoplasmic reticulum
Molecular Function:  ATP binding; ATPase activity; ATPase activity, coupled; enzyme binding; heat shock protein binding; hydrolase activity; misfolded protein binding; nucleotide binding; protein binding; protein binding involved in protein folding; protein domain specific binding; ribosome binding; ubiquitin protein ligase binding; unfolded protein binding
Biological Process:  cellular response to glucose starvation; cellular response to heat; cellular response to interleukin-4; cellular response to unfolded protein; cerebellar Purkinje cell layer development; cerebellum structural organization; chaperone cofactor-dependent protein refolding; endoplasmic reticulum unfolded protein response; ER overload response; maintenance of protein localization in endoplasmic reticulum; negative regulation of apoptotic process; negative regulation of transforming growth factor beta receptor signaling pathway; positive regulation of cell migration; positive regulation of embryonic development; positive regulation of neuron projection development; positive regulation of protein ubiquitination; posttranslational protein targeting to membrane, translocation; protein refolding; proteolysis involved in cellular protein catabolic process; response to endoplasmic reticulum stress; response to unfolded protein; toxin transport; ubiquitin-dependent ERAD pathway
Reference #:  P20029 (UniProtKB)
Alt. Names/Synonyms: 78 kDa glucose-regulated protein; AL022860; AU019543; BiP; D2Wsu141e; D2Wsu17e; Endoplasmic reticulum chaperone BiP; glucose regulated protein, 78 kDa; GRP-78; Grp78; Heat shock 70 kDa protein 5; heat shock 70kD protein 5 (glucose-regulated protein, 78kD); heat shock protein 5; Hsce70; Hspa5; Immunoglobulin heavy chain-binding protein; mBiP; OTTMUSP00000012896; OTTMUSP00000012897; SEZ-7; Sez7
Gene Symbols: Hspa5
Molecular weight: 72,422 Da
Basal Isoelectric point: 5.07  Predict pI for various phosphorylation states
Protein-Specific Antibodies or siRNAs from Cell Signaling Technology® Total Proteins
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GRP78

Protein Structure Not Found.


Cross-references to other databases:  STRING  |  Reactome  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene