Anti-GRP78

GRP78 (Glucose-regulated protein 78 kDa, also BiP and HSPA5) is a 72 kDa member of the heat shock protein 70 family of proteins. Intracellularly, GRP78 is an endoplasmic reticulum chaperone that participates in protein folding, extracellularly, it induces IL-10 production from T cells and interacts with Cripto to block TGF-beta signaling. Human GRP78 precursor is 654 amino acids (aa) in length. It contains an 18 aa signal sequence and a 636 aa mature region that shows a hydantoinase A region (aa 145-245) and a C-terminal KDEL motif that is present on intracellular GRP78, but absent on secreted GRP78. There is alternative splicing in the signal sequence (aa 1-10), and multiple single aa substitituion. Over aa 1-654, human GRP78 is more than 97% aa identical to mouse and rat GRP78.