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arXiv · 1606.07553

Actin filaments growing against a barrier with fluctuating shape

Raj Kumar Sadhu·Sakuntala Chatterjee
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Abstract

We study force generation by a set of parallel actin filaments growing against a non-rigid obstacle, in presence of an external load. The filaments polymerize by either moving the whole obstacle, with a large energy cost, or by causing local distortion in its shape which costs much less energy. The non-rigid obstacle also has local thermal fluctuations due to which its shape can change with time and we describe this using fluctuations in the height profile of a one dimensional interface with Kardar-Parisi-Zhang dynamics. We find the shape fluctuations of the barrier strongly affects the force generation mechanism. The qualitative nature of the force-velocity curve is crucially determined by the relative time-scale of filament and barrier dynamics. The height profile of the barrier also shows interesting variation with the external load. Our analytical calculation within mean-field theory shows reasonable agreement with our simulation results.

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Raj Kumar Sadhu, Sakuntala Chatterjee. 2016-06-24. Actin filaments growing against a barrier with fluctuating shape. https://doi.org/10.1103/physreve.93.062414

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