Role of ATP-hydrolysis in the dynamics of a single actin filament

Padinhateeri Ranjith (1) , Kirone Mallick (2) , Jean-François Joanny (1) , David Lacoste (3)

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

We study the stochastic dynamics of growth and shrinkage of single actin filaments taking into account insertion, removal, and ATP hydrolysis of subunits either according to the vectorial mechanism or to the random mechanism. In a previous work, we developed a model for a single actin or microtubule filament where hydrolysis occurred according to the vectorial mechanism: the filament could grow only from one end, and was in contact with a reservoir of monomers. Here we extend this approach in two ways—by including the dynamics of both ends and by comparing two possible mechanisms of ATP hydrolysis. Our emphasis is mainly on two possible limiting models for the mechanism of hydrolysis within a single filament, namely the vectorial or the random model. We propose a set of experiments to test the nature of the precise mechanism of hydrolysis within actin filaments.

Keywords: Actin; ATP hydrolysis; Stochastic dynamics

Domains: Structural Biology [q-bio.BM]; Subcellular Processes [q-bio.SC]

Padinhateeri Ranjith, Kirone Mallick, Jean-François Joanny, David Lacoste. Role of ATP-hydrolysis in the dynamics of a single actin filament. Biophysical Journal, 2010, 98 (8), pp.1418-1427. ⟨10.1016/j.bpj.2009.12.4306⟩. ⟨cea-02924677⟩