Nonequilibrium microtubule fluctuations in a model cytoskeleton.
Biological activity gives rise to nonequilibrium fluctuations in the cytoplasm of cells; however, there are few methods to directly measure these fluctuations. Using a reconstituted actin cytoskeleton, we show that the bending dynamics of embedded microtubules can be used to probe local stress fluctuations. We add myosin motors that drive the network out of equilibrium, resulting in an increased amplitude and modified time dependence of microtubule bending fluctuations. We show that this behavior results from steplike forces on the order of 10 pN driven by collective motor dynamics.
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
Clifford P
CP
Brangwynne
Gijsje H
GH
Koenderink
Frederick C
FC
Mackintosh
David A
DA
Weitz
D000199:Actins / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry*; D003198:Computer Simulation; D003599:Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism; D008954:Models, Biological; D024462:Myosin Type II / Q000737:chemistry / Q000378:metabolism; D009994:Osmolar Concentration
D000199:Actins; D024462:Myosin Type II