TY - JOUR TI - Nonequilibrium mechanics of active cytoskeletal networks. AU - Mizuno, Daisuke AU - Tardin, Catherine AU - Schmidt, C. F. AU - Mackintosh, F. C. T2 - Science (New York, N.Y.) AB - Cells both actively generate and sensitively react to forces through their mechanical framework, the cytoskeleton, which is a nonequilibrium composite material including polymers and motor proteins. We measured the dynamics and mechanical properties of a simple three-component model system consisting of myosin II, actin filaments, and cross-linkers. In this system, stresses arising from motor activity controlled the cytoskeletal network mechanics, increasing stiffness by a factor of nearly 100 and qualitatively changing the viscoelastic response of the network in an adenosine triphosphate-dependent manner. We present a quantitative theoretical model connecting the large-scale properties of this active gel to molecular force generation. DA - 2007/01/19/ PY - 2007 DO - 10.1126/science.1134404 VL - 315 IS - 5810 SP - 370 EP - 373 J2 - Science LA - eng SN - 1095-9203 0036-8075 KW - *Models, Biological KW - Actin Cytoskeleton/*physiology KW - Actins/*physiology KW - Adenosine Triphosphate/*metabolism KW - Biomechanical Phenomena KW - Cytoskeleton/*physiology KW - Elasticity KW - Mathematics KW - Molecular Motor Proteins/*physiology KW - Myosin Type II/*physiology KW - Rheology KW - Stress, Mechanical KW - Viscosity ER -