Figure 3.
Actin cytoskeletal network behaves as a viscoelastic fluid, primarily due to force-dependent binding and unbinding of cross-linker proteins and filament depolymerization. When forces are applied to filaments, cross-linker dynamics acts as a viscous friction between filaments at time scales longer than cross-linker binding rates. The network flows under force, giving a constitutive relationship as in equation (6).