78-kDa glucose-regulated protein (Binding immunoglobulin protein) (GRP78 or BiP)

GRP78/BiP is a master endoplasmic reticulum chaperone protein of the HSP70 family that guides proper folding and assembly of nascent proteins, prevents misfolding and aggregation, and targets misfolded proteins for proteasome degradation. It is central to the unfolded protein response (UPR), acting as a direct repressor of ER stress sensors, and thereby controls adaptation to cellular stress. Under disease conditions, including cancer, neurodegeneration, infection, and inflammation, GRP78 is often upregulated and can translocate to the cell surface, modulating immune signaling and serving as a viral entry point. It is increasingly recognized as a therapeutic target for diseases involving protein misfolding and ER stress

Other names

HSPA5Binding immunoglobulin protein78-kDa glucose-regulated proteinHeat shock 70 kDa protein 5BiP

Inhibition or induction of GRP78 alters protein folding, UPR signaling, and cell fate (death or survival) Modulation of cell surface localization impacts tumor cell survival and viral entry Chemical induction of GRP78 can protect cells from ER stress-mediated death