title: Nonequilibrium mechanics of active cytoskeletal networks.
abstract: 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.
authors.affiliation: Department of Physics and Astronomy, Vrije Universiteit, 1081HV Amsterdam, Netherlands.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Mizuno
authors.forename: Catherine
authors.initials: C
authors.lastname: Tardin
authors.forename: C F
authors.initials: CF
authors.lastname: Schmidt
authors.forename: F C
authors.initials: FC
authors.lastname: Mackintosh
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology*; D000199:Actins / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001696:Biomechanical Phenomena; D003599:Cytoskeleton / Q000502:physiology*; D004548:Elasticity; D008433:Mathematics; D008954:Models, Biological; D020409:Molecular Motor Proteins / Q000502:physiology*; D024462:Myosin Type II / Q000502:physiology*; D012212:Rheology; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D000199:Actins; D020409:Molecular Motor Proteins; D000255:Adenosine Triphosphate; D024462:Myosin Type II