Condensation of actin filaments pushing against a barrier

Kostas Tsekouras (1, 2) , David Lacoste (1) , Kirone Mallick (3) , Jean-François Joanny (2)

1 LPCT - Laboratoire de Physico-Chimie Théorique
2 PCC - Physico-Chimie-Curie
3 IPHT - Institut de Physique Théorique - UMR CNRS 3681

We develop a model to describe the force generated by the polymerization of an array of parallel biofilaments. The filaments are assumed to be coupled only through mechanical contact with a movable barrier. We calculate the filament density distribution and the force-velocity relation with a mean-field approach combined with simulations. We identify two regimes: a non-condensed regime at low force in which filaments are spread out spatially and a condensed regime at high force in which filaments accumulate near the barrier. We confirm a result previously known from other related studies, namely that the stall force is equal to N times the stall force of a single filament. In the model studied here, the approach to stalling is very slow, and the velocity is practically zero at forces significantly lower than the stall force.

Keywords: MICROTUBULES

Domains: Theoretical and/or physical chemistry

Kostas Tsekouras, David Lacoste, Kirone Mallick, Jean-François Joanny. Condensation of actin filaments pushing against a barrier. New Journal of Physics, 2012, 13, pp.103032. ⟨10.1088/1367-2630/13/10/103032⟩. ⟨cea-00751507⟩