title: Coordinated Movement of Vesicles and Actin Bundles during Nerve Growth Revealed by Superresolution Microscopy.
abstract: The growth cone is an essential structure for nerve growth. Although its membrane and cytoskeleton are likely to interact coordinately during nerve growth, the mechanisms are unknown due to their close proximity. Here, we used superresolution microscopy to simultaneously observe vesicles and F-actin in growth cones. We identified a novel vesicular generation mechanism that is independent of clathrin and dependent on endophilin-3- and dynamin-1 and that occurs proximal to the leading edge simultaneously with fascin-1-dependent F-actin bundling. In contrast to conventional clathrin-dependent endocytosis, which occurs distal from the leading edge at the basal surfaces of growth cones, this mechanism was distinctly observed at the apical surface using 3D imaging and was involved in mediating axon growth. Reduced endophilin or fascin inhibited this endocytic mechanism. These results suggest that, at the leading edge, vesicles are coordinately generated and transported with actin bundling during nerve growth.
authors.affiliation: Department of Neurochemistry and Molecular Cell Biology, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-ku, Niigata 951-8510, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Nozumi
authors.affiliation: Department of Neurochemistry and Molecular Cell Biology, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-ku, Niigata 951-8510, Japan; PRIME, Japan Agency for Medical Research and Development (AMED), Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Fubito
authors.initials: F
authors.lastname: Nakatsu
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Katoh
authors.affiliation: Department of Neurochemistry and Molecular Cell Biology, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-ku, Niigata 951-8510, Japan; Trans-disciplinary Research Program, Niigata University, Chuo-ku, Niigata 951-8510, Japan. Electronic address: tarokaja@med.niigata-u.ac.jp.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Igarashi
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D001369:Axons / Q000378:metabolism / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D002966:Clathrin / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D034284:Dynamin I / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D020439:Growth Cones / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D008853:Microscopy / Q000379:methods; D009419:Nerve Tissue Proteins / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000378:metabolism* / Q000502:physiology*; D022161:Transport Vesicles / Q000378:metabolism*
chemical_list: D000199:Actins; D002352:Carrier Proteins; D002966:Clathrin; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; C020324:fascin; D034284:Dynamin I
keywords: filopodia