Mica Surface Promotes the Assembly of Cytoskeletal Proteins

Abstract : We report the surface-mediated polymerization of FtsZ protein, the prokaryote homologue of tubulin, by AFM.FtsZ protein can form filaments on mica whereas the bulk FtsZ concentration is orders of magnitude lower than thecritical concentration. Surface polymerization is favored by a local increase in protein concentration and requires ahigh mobility of proteins on the surface. To generalize to other cytoskeleton protein, we also show that mica can initiatethe formation of tubulin protofilaments. This study is of particular interest for studying cytoskeletal protein dynamicsby AFM but also for the surface autoassembly of nanostructures.