title: Dynamic interaction of amphiphysin with N-WASP regulates actin assembly.
abstract: Amphiphysin 1, an endocytic adaptor concentrated at synapses that couples clathrin-mediated endocytosis to dynamin-dependent fission, was also shown to have a regulatory role in actin dynamics. Here, we report that amphiphysin 1 interacts with N-WASP and stimulates N-WASP- and Arp2/3-dependent actin polymerization. Both the Src homology 3 and the N-BAR domains are required for this stimulation. Acidic liposome-triggered, N-WASP-dependent actin polymerization is strongly impaired in brain cytosol of amphiphysin 1 knock-out mice. FRET-FLIM analysis of Sertoli cells, where endogenously expressed amphiphysin 1 co-localizes with N-WASP in peripheral ruffles, confirmed the association between the two proteins in vivo. This association undergoes regulation and is enhanced by stimulating phosphatidylserine receptors on the cell surface with phosphatidylserine-containing liposomes that trigger ruffle formation. These results indicate that actin regulation is a key function of amphiphysin 1 and that such function cooperates with the endocytic adaptor role and membrane shaping/curvature sensing properties of the protein during the endocytic reaction.
authors.affiliation: Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.forename: Sergi
authors.initials: S
authors.lastname: Padilla-Parra
authors.forename: Sun-Joo
authors.initials: SJ
authors.lastname: Park
authors.forename: Toshiki
authors.initials: T
authors.lastname: Itoh
authors.forename: Mathilde
authors.initials: M
authors.lastname: Chaineau
authors.forename: Ilaria
authors.initials: I
authors.lastname: Monaldi
authors.forename: Ottavio
authors.initials: O
authors.lastname: Cremona
authors.forename: Fabio
authors.initials: F
authors.lastname: Benfenati
authors.forename: Pietro
authors.initials: P
authors.lastname: De Camilli
authors.forename: Maïté
authors.initials: M
authors.lastname: Coppey-Moisan
authors.forename: Marc
authors.initials: M
authors.lastname: Tramier
authors.forename: Thierry
authors.initials: T
authors.lastname: Galli
authors.forename: Kohji
authors.initials: K
authors.lastname: Takei
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004705:Endocytosis; D031541:Fluorescence Resonance Energy Transfer; D005786:Gene Expression Regulation; D008081:Liposomes / Q000737:chemistry; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D012708:Sertoli Cells / Q000378:metabolism; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism*
chemical_list: D000199:Actins; D008081:Liposomes; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; C408123:phosphatidylserine receptor; C075637:amphiphysin