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Buckling, stiffening, and negative dissipation in the dynamics of a biopolymer in an active medium

Kikuchi, Norio and Ehrlicher, Allen and Koch, Daniel and Kaes, Josef A. and Ramaswamy, Sriram and Rao, Madan (2009) Buckling, stiffening, and negative dissipation in the dynamics of a biopolymer in an active medium. In: Proc Natl Acad Sci Unit States Am, 106 (47). pp. 19776-19779.

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Official URL: http://www.pnas.org/content/106/47/19776.abstract


We present a generic theory for the dynamics of a stiff filament under tension, in an active medium with orientational correlations, such as a microtubule in contractile actin. In sharp contrast to the case of a passive medium, we find the filament can stiffen, and possibly oscillate or buckle, depending on both the contractile or tensile nature of the activity and the filament-medium anchoring interaction. We also demonstrate a strong violation of the fluctuation-dissipation (FD) relation in the effective dynamics of the filament, including a negative FD ratio. Our approach is also of relevance to the dynamics of axons, and our model equations bear a remarkable formal similarity to those in recent work [Martin P, Hudspeth AJ, Juelicher F (2001) Proc Natl Acad Sci USA 98: 14380-14385] on auditory hair cells. Detailed tests of our predictions can be made by using a single filament in actomyosin extracts or bacterial suspensions.

Item Type: Journal Article
Publication: Proc Natl Acad Sci Unit States Am
Publisher: National Academy of Sciences.
Additional Information: Copyright of this article belongs to National Academy of Sciences.
Keywords: cytoskeleton;active hydrodynamics;microrheology;fluctuation-dissipation ratio;neuronal growth cone.
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Date Deposited: 11 Jan 2010 08:03
Last Modified: 19 Sep 2010 05:53
URI: http://eprints.iisc.ac.in/id/eprint/25259

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