Reconstitution of the transition from lamellipodium to filopodium in a membrane-free system

• DOI: 10.1073/pnas.0508269103
• Publication Date: 2006-03-21T01:44:26Z
• Authors: Lior Haviv; Yifat Brill-Karniely; Rachel Mahaffy; Frederic Backouche; Avinoam Ben-Shaul; Thomas D. Pollard; Anne Bernheim-Gro...
• Keywords: Filopodia; Lamellipodium; MDia1; Fascin; Actin remodeling; Pseudopodia; Profilin

The cellular cytoskeleton is a complex dynamical network that constantly remodels as cells divide and move. This reorganization process occurs not only at the cell membrane, but also in interior (bulk). During locomotion, regulated actin assembly near plasma membrane produces lamellipodia filopodia. Therefore, most vitro experiments explore phenomena taking place vicinity of surface. To understand how molecular machinery self-organizes more general way, we studied bulk polymerization presence actin-related protein 2/3 nucleation promoting factor model for separate from membranes. Bulk verprolin homology, cofilin acidic region, domain Wiskott-Aldrich syndrome protein, results spontaneous formation diffuse aster-like structures. In fascin these asters transition into stars with bundles filaments growing surface, similar to star-like structures recently observed vivo . depends on ratio [fascin]/[G actin]. polarity during preserved, Capping inhibits star formation. Based kinetic Monte Carlo simulations, propose self-assembly their stars. mechanism may apply filopodia