Abstract

In vertebrate and invertebrate nonmuscle myosins, light‐ and heavy‐chain phosphorylation regulate myosin assembly into filaments, and interaction with actin. Vertebrate non‐muscle myosins can exist in vitro in three main states, either ‘folded’ (assembly‐blocked) or ‘extended’ (assembly‐competent) monomers, and filaments. Light‐chain phosphorylation regulates the ‘dynamic equilibrium’ between these states. The ability of the myosin to undergo changes in conformation and state of assembly may be an important mechanism in regulating the organization of the cytoskeleton and cell motility.