Force generation in lamellipodia is a probabilistic process with fast growth and retraction events

Shahapure, Rajesh and Difato, Francesco and Laio, Alessandro and Bisson, Giacomo and Ercolini, Erika and Amin, Ladan and Ferrari, Enrico and Torre, Vincent (2010) Force generation in lamellipodia is a probabilistic process with fast growth and retraction events. Biophysical Journal, 98 (6). pp. 979-988. ISSN 0006-3495

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Full text URL: http://dx.doi.org/10.1016/j.bpj.2009.11.041

Abstract

Polymerization of actin filaments is the primary source of motility in lamellipodia and it is controlled by a variety of regulatory proteins. The underlying molecular mechanisms are only partially understood and a precise determination of dynamical properties of force generation is necessary. Using optical tweezers, we have measured with millisecond (ms) temporal resolution and picoNewton (pN) sensitivity the force-velocity (Fv) relationship and the power dissipated by lamellipodia of dorsal root ganglia neurons. When force and velocity are averaged over 3–5 s, the Fv relationships can be flat. On a finer timescale, random occurrence of fast growth and subsecond retractions become predominant. The maximal power dissipated by lamellipodia over a silica bead with a diameter of 1 μm is 10−16 W. Our results clarify the dynamical properties of force generation: i), force generation is a probabilistic process; ii), underlying biological events have a bandwidth up to at least 10 Hz; and iii), fast growth of lamellipodia leading edge alternates with local retractions.

Item Type:Article
Keywords:optical tweezers, lamellipodia, actin
Subjects:C Biological Sciences > C770 Biophysical Science
B Subjects allied to Medicine > B140 Neuroscience
Divisions:College of Science > School of Life Sciences
ID Code:6585
Deposited By: Enrico Ferrari
Deposited On:15 Oct 2012 20:47
Last Modified:02 Jan 2014 13:02

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