Fig. 5. A modified model of cytoskeletal force transduction yields mechanical equilibrium at individual integrins.

(A) Simplified cartoon of a FA: Nonmuscle myosin II pulls on reversibly cross-linked actin filaments, which are linked to integrins by vinculin and talin. (B) Cytoskeletal dynamics model: F-actin filaments bind to anchors (blue) and are linked by cross-linking proteins (green). (C) An example force trace of the standard clutch model and possible clutch model extensions that account for multivalent clutch connections, viscous relaxation, or reversible cross-links. Reversible cross-links allow for stable force plateaus as well as sporadic ramp and step events. The dashed gray lines indicate zero force. (D) Calculated energy dissipation from simulations with irreversible (top) and reversible (bottom) cross-links. (E) Force distribution for simulated anchors with reversible cross-linking (k_x,off = 20 s⁻¹).