Neural Wiskott-Aldrich syndrome protein, WASL, WASP
Members of the Wiskott-Aldrich sydrome protein (WASP) family regulate the formation of actin-based cell structures in many cell types. These proteins contain C-terminal actin-binding domains that can stimulate actin polymerization. In addition, these proteins bind the ARP2/3 complex, which can nucleate actin polymerization at sites that lead to branched actin structures. WASP is expressed primarily in hematopoietic cells, while its homolog N-WASP is widely expressed. These proteins have 48% identity in human with the highest homology in the functional regions of these proteins. Phosphorylation regulates the activity of both proteins. Dual phosphorylation of WASP on serine 483 and 484 by casein kinases increase the affinity for the ARP2/3 complex. Thus, dual serine phosphorylation may be important for formation of actin-based structures in various cell types
