Search by BoMiProt ID - Bomi138

Primary Information

BoMiProt ID Bomi138
Protein Name 78 kDa glucose-regulated protein
Organism Bos taurus
Uniprot IdQ0VCX2
Milk FractionWhey
Ref Sequence Id NP_001068616.1
Amino Acid Lenth 655
Molecular Weight 72400
Fasta Sequence
Gene Name HSPA5
Gene Id 415113
Protein Existence Status Reviewed: Experimental evidence at transcript level

Secondry Information

Protein Function immunoglobulin heavy chain binding protein1 and as the glucose regulated protein; ER-located member of the family of HSP70 molecular chaperones; binds transiently to newly-synthesized proteins in the ER and more permanently to misfolded, underglycosylated or unassembled proteins whose transport from the ER is blocked; assists the folding and assembly of newly-synthesized proteins by recognising unfolded polypeptides and, by inhibiting intra- or intermolecular aggregation, maintaining them in a state competent for subsequent folding and oligomerisation; maintain the permeability barrier of the ER membrane by sealing the lumenal end of the translocon pore before and early in translocation; required during ara cell mating for the stage of karyogamy that involves fusion of the nuclear membranes of Saccharomyces cerevisiae
Biochemical Properties BiP does not interact with native polypeptides; two major domains, an N-terminal domain that contains the ATPase catalytic site and a C-terminal substrate bind- ing domain; domains communicate to regulate the affinity and duration of poly.peptide binding; In vitro, BiP can interact with short synthetic peptides whose binding stimulates its ATPase activity and alters its oligomeric state; interacts with sequences normally located in the interior of a fully-folded protein; presence of a heptameric motif with a bulky aromatic or hydrophobic residue most frequently tryptophan, phenylalanine or leucine, but also methionine and isoleucine.
Significance in milk required for mammary gland development; contributes to the regulation of Cripto signaling in mammary stem cells; . Grp78 heterozygosity impeded transgene-induced mammary tumor development, with the tumors showing reduced proliferation, increased apoptosis, and dramatic reduction of tumor angiogenesis
PTMs mammalian BiP exists in interconvertible monomeric and oligomeric forms and can be post-translationally modified by phosphorylation and by ADP ribosylation
Significance of PTMs important in regulating the synthesis and polypeptide binding activity of the molecule; conditions that increase the levels of unfolded polypeptides in the ER lumen cause a decrease in the extent of modification of BiP and an increase in the proportion of monomeric species; post-translational modification of BiP appears to provide a storage pool of BiP that can be recruited back to the active form in response to need
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