Type-I myosin implicated in the organization of the actin cytoskeleton. Required for proper actin cytoskeleton polarization. At the cell cortex, assembles in patch-like structures together with proteins from the actin-polymerizing machinery and promotes actin assembly. Functions as actin nucleation-promoting factor (NPF) for the Arp2/3 complex (By similarity). The myosin motor domain displays actin-stimulated ATPase activity and generates a mechanochemical force. The tail domain participates in molecular interactions that specify the role of the motor domain (By similarity). It is composed of several tail homology (TH) domains, namely a putative phospholipid-binding myosin tail domain (also named TH1), an Ala- and Pro-rich domain (TH2), followed by an SH3 domain and a C-terminal acidic domain (TH3). Phosphorylation of the TEDS site (Ser-358) is required for the polarization of the actin cytoskeleton. Phosphorylation probably activates the myosin-I ATPase activity (By similarity). Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Myosin family.