Direct observation of dendritic actin filament networks nucleated by Arp2/3 complex and WASP/Scar proteins

摘要: Most nucleated cells crawl about by extending a pseudopod that is driven the polymerization of actin filaments in cytoplasm behind leading edge plasma membrane. These are linked into network Y-branches, with pointed end each filament attached to side another and rapidly growing barbed facing forward. Because Arp2/3 complex nucleates links vitro, dendritic nucleation model has been proposed which initiates from sides older filaments. Here we report, using light microscopy assay, many new features mechanism. Branching occurs during, rather than after, activated Wiskott-Aldrich syndrome protein (WASP) or Scar protein; capping profilin act synergistically favour branched nucleation; phosphate release aged favours dissociation ends filaments; branches created relatively rigid. properties result automatic assembly after activation proteins WASP/Scar family selective disassembly proximal regions network.