Indirect repulsion between actin binding proteins induces the local pattern formation of protein clusters

A periodic pattern composed of alternating myosin II and α-actinin clusters forms along the stress fibers in live cells. Here, we propose that the indirect repulsion between these proteins is able to lead to the formation of the periodic pattern. We use a coarse-grained Kinetic Monte Carlo method to investigate the effect of the repulsion strength. The simulation results reproduce the phase separation of these proteins as well as the dynamics of the cluster growth observed in experiments. Meanwhile, a double-S feature emerges during the cluster growth when the repulsion strength is high, indicating that the system undergoes a transition from an intermediate state to the final state. The good agreement between our simulations and the published experimental observations suggests that the indirect repulsion might play an important role during the pattern formation of proteins along the stress fibers.