Activation of the Arp2/3 Complex by WASP Family Proteins: Probing Individual Subunits by NMR

The Rho-family GTPases regulate the actin cytoskeleton through activation of the Wiskott-Aldrich Syndrome protein (WASP) family proteins, and they in turn activate the Actin-related protein (Arp) 2/3 complex. It has been postulated that the C-terminal WA domain (containing the WASP homology 2 (WH2) domain and acidic tail) of WASP proteins induces a conformational change in Arp2/3 that renders it competent to nucleate the polymerization of a new actin filament.