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. Serine and tyrosine phosphorylation regulates the activity of both proteins. WASP is observed as a 63 kDa protein in hematopoietic cells, while N-WASP is observed as a 65 kDa in many tissues, especially brain.