Figure 3.

Two evolutionarily distinct functions for Hsp90 family proteins. Intracellular Hsp90, especially Hsp90β, is a chaperone that requires its intrinsic ATPase activity. Its purpose is to maintain the signaling networks in working condition. Extracellular Hsp90, especially Hsp90α, is a promotility factor that uses the F-5 region in an ATPase-independent manner. Its purpose is to help repair damaged tissue. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound