Intracellular Transport on Dynamic Actin Networks

Recently there has been an explosion of new studies that target transport on networks of filaments. This has been driven by advances in experimental techniques that have provided clearer and more controllable in vivo and in vitro studies. However, one aspect that has received much less attention is the growth/shrinkage and dynamic turnover of the network filaments themselves, which can occur on the same time scale as the transport of cargo on the network. Consequently, the complex intracellular dynamics of the inhomogeneous cytoskeletal structure can have profound impacts on transport. Here, we study transport of cargo carried by myosin motors on a dynamic actin network. We use a stochastic simulation model that accounts for both active transport along filaments as well as passive diffusion and incorporates the dynamics of the explicitly represented actin network. We study how filament growth/shrinkage velocity, for actin treadmilling, effect cargo transport along with motor attachment/detachment rates. We will vary the density and the location and distribution of F-actin to ascertain how these variations change the optimal transport of cargo. This analysis will illuminate how actin dynamics can be used to modulate optimality in the molecular transport of cellular cargo.