Regulation of Actin Bundle Mechanics and Structure by Intracellular Environmental Factors

• DOI: 10.3389/fphy.2021.675885
• Publication Date: 2021-05-27T13:27:36Z
• Authors: Nicholas Castaneda; Jinho Park; Ellen Hyeran Kang
• Keywords: cation interactions; 0303 health sciences; 03 medical and health sciences; macromolecular crowding; actin crosslinker; actin bundles; Physics; QC1-999; bending stiffness; Article

The mechanical and structural properties of actin cytoskeleton drive various cellular processes, including structural support of the plasma membrane and cellular motility. 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. Although the roles of each of these factors in actin bundling have been well-known individually, how combined factors contribute to actin bundle assembly, organization, and mechanics is not fully understood. Here, we describe recent studies that have investigated the mechanisms of how intracellular environmental factors influence actin bundling. This review highlights the effects of macromolecular crowding, cation interactions, and actin-crosslinking proteins on actin bundle organization, structure, and mechanics. Understanding these mechanisms is important in determining in vivo actin biophysics and providing insights into cell physiology.