Regulation of actin cytoskeleton mechanics and structure by intracellular environmental factors

The mechanical and structural properties of the actin cytoskeleton drive many cellular processes, including structural support of the plasma membrane, cell motility, and force generation. Actin monomers assemble into double-stranded helical filaments as well as higher-ordered structures such as bundles and networks. Cells incorporate macromolecular crowding, cation interactions, and actin-crosslinking proteins to regulate the organization of actin bundles and networks. Although the roles of each of these intracellular environmental factors in actin assembly dynamics have been shown individually, how combined factors contribute to the organization and mechanics of actin cytoskeleton is not well established. We investigate the mechanisms of how intracellular environmental factors influence actin cytoskeleton mechanics and structure. In particular, the effects of macromolecular crowding, cation interactions, and actin-crosslinking proteins on actin bundle organization, structure, and mechanics will be highlighted. Understanding these molecular mechanisms will allow us to better understand how changes in actin mechanics and structure are linked to cell physiology as well as human disease states.