title: Exo70 stimulates the Arp2/3 complex for lamellipodia formation and directional cell migration.
abstract: Directional cell migration requires the coordination of actin assembly and membrane remodeling. The exocyst is an octameric protein complex essential for exocytosis and plasma membrane remodeling. A component of the exocyst, Exo70, directly interacts with the Arp2/3 complex, a core nucleating factor for the generation of branched actin networks for cell morphogenesis and migration. Using in vitro actin polymerization assay and time-lapse total internal reflection fluorescence microscopy, we found that Exo70 functions as a kinetic activator of the Arp2/3 complex that promotes actin filament nucleation and branching. We further found that the effect of Exo70 on actin is mediated by promoting the interaction of the Arp2/3 complex with WAVE2, a member of the N-WASP/WAVE family of nucleation promoting factors. At the cellular level, the stimulatory effect of Exo70 on the Arp2/3 complex is required for lamellipodia formation and maintaining directional persistence of cell migration. Our findings provide a novel mechanism for regulating actin polymerization and branching for effective membrane protrusion during cell morphogenesis and migration.
authors: Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors: Jianglan
authors: J
authors: Liu
authors: Yuting
authors: Y
authors: Zhao
authors: Yujie
authors: Y
authors: Sun
authors: Bing
authors: B
authors: He
authors: Changsong
authors: C
authors: Yang
authors: Tatyana
authors: T
authors: Svitkina
authors: Yale E
authors: YE
authors: Goldman
authors: Wei
authors: W
authors: Guo
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D006801:Humans; D058105:Polymerization; D011554:Pseudopodia / Q000502:physiology*; D051381:Rats; D033921:Vesicular Transport Proteins / Q000378:metabolism*; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; C109901:Exoc7 protein, rat; D033921:Vesicular Transport Proteins; D051300:Wiskott-Aldrich Syndrome Protein Family