Abstract
Motor proteins actively contract the actin cytoskeleton of cells and thereby give rise to nonequilibrium fluctuations as well as changes in the architecture of the cytoskeleton. Here, we show, by video microrheology of a reconstituted cytoskeleton, that motors generate time-dependent nonequilibrium fluctuations, which evolve as the network is remodeled. At earlier times, the fluctuation spectrum is dominated by strong non-Gaussian fluctuations, which arise from large displacements. At later times, directed displacements are infrequent and finally disappear. We show that these effects are due to contractile coarsening of the network into large actin-myosin foci.
- Received 13 April 2012
DOI:https://doi.org/10.1103/PhysRevE.86.020901
©2012 American Physical Society
Synopsis
The Skeleton Dance
Published 23 August 2012
Experiments can see how motor proteins direct the movements of the cell’s cytoskeleton in a fluctuating environment.
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