What is the function of HSP90?
Hsp90 is a highly abundant and ubiquitous molecular chaperone which plays an essential role in many cellular processes including cell cycle control, cell survival, hormone and other signalling pathways. It is important for the cell’s response to stress and is a key player in maintaining cellular homeostasis.
Why is HSP90 important for receptors?
Hsp90 stabilizes various growth factor receptors and some signaling molecules including PI3K and AKT proteins. Hence inhibition of Hsp90 downregulates the PI3K/AKT pathway leading to downregulation of the anti-apoptotic protein Bcl-w resulting in apoptosis of cancerous and senescent cells.
What are chaperone proteins and what is their function?
Chaperones are a functionally related group of proteins assisting protein folding in the cell under physiological and stress conditions. They share the ability to recognize and bind nonnative proteins thus preventing unspecific aggregation.
How do HSP90 inhibitors work?
Natural product inhibitors HSP90 has conserved unique pocket in N terminal region. It binds ATP & ADP and has weak ATPase activity. Addition of such inhibitor causes proteosomal degradation of signaling proteins like steroid receptors, Raf kinase and Akt.
How is Hsp90 activated?
Heat shock protein 90 (Hsp90) is a molecular chaperone that is involved in the activation of disparate client proteins. Perhaps the most important regulator is heat shock factor 1 (HSF1), which is primarily responsible for upregulating Hsp90 by binding heat shock elements (HSEs) within Hsp90 promoters.
Where is Hsp90 found?
Two forms, HSP90 alpha and HSP90 beta, are located in the cytoplasm, GRP94 (94-kDa glucose-regulated protein) exists in the ER, and TRAP-1 (tumor necrosis factor receptor-associated protein 1) is present in the mitochondria.
What process does a chaperone facilitate in the cell?
Molecular chaperones facilitate protein folding and are particularly required for large proteins and protein complexes. Therefore, the E. coli cell-free protein synthesis system is supplemented with E. coli or eukaryotic molecular chaperones, to achieve the correct folding of the product protein.
Is Hsp90 a transcription factor?
Hsp90 governs the transcription factor network controlling chromatin status. Hsp90 mediates a late folding step required for transcription factor DNA-binding activity. Hsp90 supports the steady-state stability of transcription factor proteins.
Is Hsp90 a dimer?
At physiological concentration, Hsp90 predominantly forms dimers, but the function of full-length monomers in cells is not clear. Hsp90 contains three domains: the N-terminal and middle domains contribute directly to ATP binding and hydrolysis and the C domain mediates dimerization.
Is Hsp90 a gene?
Tocris Summary for HSP90AB1 Gene Hsp90 (90 kDa heat shock protein) is a molecular chaperone that aids protein folding and quality control for a large number of ‘client’ proteins. Hsp90 operates as dimer and has intrinsic ATPase activity. The Hsp90 dimer acts in concert with other chaperones (e.g. Hsp70).
