HSP90beta polyclonal antibody from MyBioSource.com

The 90 kDa molecular chaperone family includes 90 kDa heat shock protein Hsp90 and 94 kDa glucose-regulated protein grp94, both major molecular chaperones of the cytosol and the endoplasmic reticulum. Mammalian cells express inducible Hsp90 alpha and constitutive Hsp90 beta isoforms that are encoded by separate genes. The amino acid sequences of human and yeast Hsp90 alpha are 85% and 90% homologous to those of Hsp90 beta, respectively. All known members of the Hsp90 protein family are highly conserved, especially in the N-terminal and C-terminal regions containing independent chaperone sites with different substrate specificity. These ubiquitous and highly conserved proteins account for 1-2% of all cellular protein in most cells. Hsp90 functions as part of the cell's powerful network of chaperones to fight the deleterious consequences of protein unfolding caused by non-physiological conditions. In the absence of stress, however, Hsp90 provides a necessary component of such fundamental cellular processes as hormone signaling and cell cycle control by serving as a chaperone for many key signaling molecules including steroid receptors, cell cycle kinases involved in signal transduction, and p53. As many of these client proteins are known oncogenes, Hsp90 inhibitors such as 17-AAG, a geldanamycin analog, have been of benefit in the treatment of many cancers