Berlin 2008 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 24: Actin Dynamics

BP 24.1: Hauptvortrag

Donnerstag, 28. Februar 2008, 14:00–14:30, C 243

A biochemical reconstitution approach of the coordinated actin assembly dynamics in motile and morphogenetic processes. — •Marie-France Carlier, Louis Renault, Guillaume Romet-Lemonne, Emmanuele Helfer, Beata Bugyi, Kim Ho Diep Le, Dominique Didry, and Stéphane Romero — CNRS, Gif-sur-Yvette, France

In living cells, the actin cytoskeleton is composed of polar actin filaments that are assembled at a steady state in well organized arrays, and co-exist with a pool of monomeric actin. Filaments turnover via a treadmilling mechanism, in which the pool of polymerizable monomeric ATP-actin, generated by pointed end depolymerization of all filaments in these arrays, drives the growth of filament barbed ends. Filament barbed end growth is also controlled by machineries that link signalling to the actin cytoskeleton. We are interested in understanding the physical chemical principles underlying the coordinated turnover of actin filaments in these different meshworks and their synergetic action in motility and porphogenetic processes. For this we propose a systemic biology approach. I will show a few examples as follows. In vitro reconstitution assays of actin-based propulsion of N-WASP-functionalized beads or liposomes illustrate the role of the interplay between membrane and cytoskeleton dynamics in directional movement ; reconstitution of the rapid processive assembly of filaments profilin-actin by immobilized formins mimicks filopodia extension ; reconstitution of the synergy between Spire and formin suggests a possible functional basis of the genetic interplay between these two proteins in embryogenesis.