Dynamic interaction of amphiphysin with N-WASP regulates actin assembly.
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.
Yamada
Hiroshi
H
Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
Padilla-Parra
Sergi
S
Park
Sun-Joo
SJ
Itoh
Toshiki
T
Chaineau
Mathilde
M
Monaldi
Ilaria
I
Cremona
Ottavio
O
Benfenati
Fabio
F
De Camilli
Pietro
P
Coppey-Moisan
Maïté
M
Tramier
Marc
M
Galli
Thierry
T
Takei
Kohji
K
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*
D000199:Actins; D008081:Liposomes; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; C408123:phosphatidylserine receptor; C075637:amphiphysin