Activator Of 90kDa Heat Shock Protein ATPase Homolog 2 (AHSA2)

AHSA2 is a human gene which encodes a protein which acts as co-chaperone of Hsp90 (heat shock protein 90). AHSA2 and the related AHSA1 belongs to the AHA (Activator of Hsp90 ATPase) family of stress-regulated proteins that bind directly to Hsp90 and are required for Hsp90-dependent activation of client proteins. Client protein activation by Hsp90 involves a plethora of cochaperones whose roles are poorly defined. A ubiquitous family of stress-regulated proteins have been identified (Aha1, activator of Hsp90 ATPase) that bind directly to Hsp90 and are required for the in vivo Hsp90-dependent activation of clients such as v-Src, implicating them as cochaperones of the Hsp90 system. In vitro, Aha1 and its shorter homolog, Hch1, stimulate the inherent ATPase activity of yeast and human Hsp90.