Modeling mechanical-force transmission and interactions of myosin motors in the disordered cytoskeleton network

Myosin molecular motors actively generate contractile forces in the actin cytoskeleton of animal cells that drive biological processes. These forces can be transmitted at long range through force chains that form in the elastic, disordered, cytoskeletal network. We model the disordered cytoskeletal network around an actin bundle as a mechanical fiber network comprising linear elastic fiber elements that can be bent or stretched, and that buckle above a critical compression threshold, which captures its anisotropic and nonlinear elastic properties.
We show by numerically minimizing the total elastic energy of the network that it mediates mechanical interactions between distant actomyosin units leading to favorable spatial configurations of motors, including possibly the recently observed registry of myosin in cells. We
then extend the model to a line of equally spaced force dipoles representing a stress fiber, and explore its elastic interaction energy with a distant force dipole as a function of its position and orientation, to show that mechanical forces promote stress fiber assembly by promoting
actomyosin alignment and registry. In future, we will extend our model to describe the force-dependent remodeling dynamics of the actomyosin structures of the cytoskeleton.