Effects of Confinement and Crosslinking on the Organization of Actin Networks

The actin cytoskeleton is vital to cellular processes such as the molecular motor-driven transport of organelles within cells. Crosslinking proteins organize actin filaments into bundles, affecting the local and global architecture of the actin filament network and influencing intracellular transport. In plant cells, the actin cytoskeleton is vital for bulk, cellular-scale transport known as cytoplasmic streaming. However, much remains unknown about how confinement and crosslinking by proteins such as plant villin influence cytoskeletal organization and intracellular transport in plant cells. In this work, we use hybrid computational methods utilizing kinetic Monte Carlo and Brownian dynamics simulations to study the organization of actin networks as a function of system size, system shape, and density of crosslinking proteins. Using tools from graph theory, we gain insight into cytoskeletal architecture by analyzing graphs characterizing the connectivity of actin networks. Finally, we examine the influence of resulting network structures on dynamics of molecular motor motion.