Activator of 90 kDa heat shock protein ATPase homolog 1 (AHSA1)

Acts as a co-chaperone of HSP90AA1 (PubMed:29127155).

Activates the ATPase activity of HSP90AA1 resulting in increase in its chaperone activity (PubMed:29127155).

Competes with the inhibitory co-chaperone FNIP1 for binding to HSP90AA1, thereby providing a mutual regulatory mechanism for chaperoning of client proteins (PubMed:27353360). Competes with the inhibitory co-chaperone TSC1 for binding to HSP90AA1, thereby providing a mutual regulatory mechanism for chaperoning of client proteins (PubMed:29127155).