Heat shock protein 90kDa beta member 1 (HSP90B1), known also as endoplasmin, gp96, grp94, or ERp99, is a chaperone protein that in humans is encoded by the HSP90B1 gene. [5] [6]
HSP90B1 is an HSP90 paralogue that is found in the endoplasmic reticulum. It plays critical roles in folding proteins in the secretory pathway such as Toll-like receptors and integrins. [7] [8] It has been implicated as an essential immune chaperone to regulate both innate and adaptive immunity. [9] Tumor-derived HSP90B1 (vitespen) has entered clinical trials for cancer immunotherapy. [10] [11] [12] [13]
grp94 has been shown to be a target for treatment of a plethora of diseases such as glaucoma, multiple myeloma, and metastatic cancer. grp94 includes 5 distinct amino acids in its primary sequence which creates 2 unique sub-pockets, S1 and S2. These sub-pockets have been utilized in current research in order to inhibit the chaperone since its client proteins seem to be up-regulated in cancer cells. [14]
GP96 Heat Shock Protein-Peptide Complex Vaccine in Treating Patients With Recurrent or Progressive Glioma