Figure 9.

Myosin cluster sizes are set by a limiting pool of myosin that is available for cluster growth. Myosin filaments independent of ROCK activity nucleate myosin clusters. ROCK activity increases myosin assembly, which increases the pool of myosin available for cluster growth through increased net association. Myosin motor activity further enhances myosin cluster growth through F-actin-dependent myosin association. Myosin cluster sizes are perturbed when thin F-actin meshworks are depleted by LatA. To see this figure in color, go online.