GRP94 (Glucose-Regulated Protein 94), also known as HSP90B1 or gp96. is a member of the heat shock protein 90 (HSP90) family. It resides primarily in the endoplasmic reticulum (ER) and functions as a molecular chaperone, facilitating the folding and assembly of secreted and transmembrane proteins, including integrins, Toll-like receptors, and immunoglobulins. Unlike cytosolic HSP90 isoforms, GRP94 contains an ER-retention motif (KDEL) and plays a critical role in ER stress responses, calcium homeostasis, and the unfolded protein response (UPR).
Antibodies targeting GRP94 are essential tools for studying its expression, localization, and interactions. They are widely used in techniques like Western blotting, immunoprecipitation, and immunofluorescence to investigate GRP94's involvement in diseases such as cancer, autoimmune disorders, and neurodegenerative conditions. GRP94 is often overexpressed in tumors, where it supports oncoprotein stability and tumor survival, making it a potential therapeutic target. Specific antibodies help distinguish GRP94 from other HSP90 family members (e.g., HSP90α/β) and assess its functional roles.
Research also explores GRP94 antibodies for therapeutic applications. Monoclonal antibodies blocking GRP94-client interactions or disrupting its chaperone activity have shown promise in preclinical cancer models. Additionally, GRP94’s role in antigen presentation links it to immune modulation, inspiring antibody-based strategies for vaccine development. These antibodies are typically validated for species reactivity (e.g., human, mouse) and application-specific performance to ensure specificity.