Polarisation and cell movement: a multiscale modelling approach

Cell motility is a complex phenomenon, in which the cytoskeleton and its major constituent, actin, play an essential role. To understand the intricated interplay which brings about cell motility, we use a multiscale modelling approach in a 2D model of a motile cell. We describe the mutual interactions of the small G-proteins, and their effects on capping and side-branching of actin filaments. We incorporate the pushing exerted by oriented actin filament ends on the cell edge, and a Rho-dependent contraction force. Combining these biochemical and mechanical aspects, we investigate the dynamics of a model epidermal fish keratocyte through emph{in silico} experiments. Our model gives insight into how, in response to some cue, a cell can polarise, form a leading edge, and move; concomitantly it explains how a keratocyte cell can maintain its shape and polarity, even after removal of the initial stimulus, and how it can change direction quickly in response to changes in its environment. This is joint work with Alexandra Jilkine, Adriana Dawes, and Leah Keshet, and was funded by NSERC, MITACS, NWO and NSF.