Dynamic interaction of amphiphysin with N-WASP regulates actin assembly.

Journal article

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: Yamada, H; Padilla-Parra, S; Park, S; Itoh, T; Chaineau, M

• Journal: Journal of biological chemistry
• Volume: 284
• Issue: 49
• Pages: 34244-34256
• Publication date: 2009-12-01
• DOI: 10.1074/jbc.m109.064204
• EISSN: 1083-351X
• ISSN: 0021-9258
• Language: English
• Keywords: Cytosol; Wiskott-Aldrich Syndrome Protein, Neuronal; Nerve Tissue Proteins; Endocytosis; Mice; Gene Expression Regulation; Fluorescence Resonance Energy Transfer; Animals; Mice, Knockout; Brain; Liposomes; Male; Actins; Receptors, Cell Surface; Sertoli Cells; Cell Membrane; Rats