FIGURE 1:

Schematic representation of the domain structure of mammalian type I myosin, Myo1E. Myo1E is composed of an N-terminal motor domain, a neck domain with IQ calmodulin-binding motif, a tail domain with tail-homology (TH) 1 and 2 domains, and a Src-homology (SH3) domain. Budding yeast Myo3/5 proteins have similar domain structures to the mammalian orthologue, Myo1E, except for the addition of a C-terminal (C) and acidic (A) domain. The A and C domains are necessary to activate the yeast Arp2/3 complex for actin polymerization. Mammalian WASP-interacting protein family 1/2 (WIPF1/2), commonly known as WIP and WIRE, related to yeast verprolin (Vrp1), is composed of two WASP-homology 2 (WH2) domains in the N-terminal verprolin-homology domain (V domain), a proline-rich domain (PRD), and a C-terminal WASP/N-WASP–binding domain. Mammalian N-WASP is composed of an N-terminal WIP-binding WASP-homology 1 (WH1) domain, a basic region (B), a GTPase-binding domain (GBD), a PRD, and a C-terminal VCA domain.