Nonequilibrium Mechanics of Active Cytoskeletal Networks
Daisuke Mizuno,1
Catherine Tardin,1
C. F. Schmidt,1,2*
F. C. MacKintosh1*
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.
1 Department of Physics and Astronomy, Vrije Universiteit, 1081HV Amsterdam, Netherlands.
2 III. Physikalisches Institut, Fakultät für Physik, Georg-August-Universität, 37077 Göttingen, Germany.
* To whom correspondence should be addressed. E-mail: cfs{at}nat.vu.nl (C.F.S.); fcm{at}nat.vu.nl (F.C.M.)
