The actin cytoskeleton is a crucial biological system that plays a role in cell division, motion, and internal transport. The main component is filamentous actin, a semiflexible polymer formed of  proteins called actin monomer.   For  a  cell  to  regulate  and  accomplish the tasks of the cytoskeleton, actin polymers are organized into structures by actin binding proteins. Crosslinking proteins join actin into a network with structural rigidity, and form tight bundles that are more stiff than single filaments.  Different crosslinkers perform diverse functions in cells, and their spatial localization is crucial for those functions. 

In this talk, I will first describe a general simulation framework we have developed for studying the structure and mechanics of active crosslinked filament networks, such as the actin cytokeleton. I will then describe how we have used this simulation framework in conjunction with theory and Monte Carlo simulations of a lattice model to study the physical driving forces underlying a newly mechanism by which different actin crosslinking proteins can sort themselves.