A novel dynamin-associating molecule, formin-binding protein 17, induces tubular membrane invaginations and participates in endocytosis.
Dynamin associates with a variety of SH3 domain-containing molecules via a C-terminal proline-rich motif and takes part, with them, in endocytic processes. Here, we have investigated a new dynamin-associating molecule, formin-binding protein 17 (FBP17), involved in deforming the plasma membrane and in endocytosis. FBP17 formed tubular invaginations originating from the plasma membrane. Its N-terminal Fer/CIP4 homology domain, a coiled-coil domain, and a proline-rich motif were required for tubular invagination and self-assembly, by which tubular invagination might be induced. Using anti-FBP17 antibody, we detected positive immunoreactions in the testis that were restricted to the germ cells. We also detected FBP17 in the brain by immunoblotting and in situ hybridization. When COS cells expressing enhanced green fluorescent protein-tagged FBP17 were incubated with fluorescently labeled transferrin, epidermal growth factor, and cholera toxin, these molecules co-localized with FBP17-induced tubular invaginations, suggesting that FBP17 is involved in dynamin-mediated endocytosis in both a clathrin-dependent and -independent manner. These observations therefore indicate that FBP17 interacts with dynamin and regulates endocytosis by forming vesicotubular structures.
Kamioka
Yuji
Y
Department of Structural Analysis, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Fukuhara
Shigetomo
S
Sawa
Hirofumi
H
Nagashima
Kazuo
K
Masuda
Michitaka
M
Matsuda
Michiyuki
M
Mochizuki
Naoki
N
D000818:Animals; D001921:Brain / Q000378:metabolism; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002772:Cholera Toxin / Q000493:pharmacokinetics; D034281:Dynamins / Q000378:metabolism*; D004705:Endocytosis / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000493:pharmacokinetics; D050556:Fatty Acid-Binding Proteins; D006801:Humans; D008297:Male; D051379:Mice; D013737:Testis / Q000378:metabolism; D014168:Transferrin / Q000493:pharmacokinetics; D018909:src Homology Domains / Q000502:physiology
D002352:Carrier Proteins; C433770:FNBP1 protein, human; D050556:Fatty Acid-Binding Proteins; D014168:Transferrin; D004815:Epidermal Growth Factor; D002772:Cholera Toxin; D034281:Dynamins