title: Drosophila Strip serves as a platform for early endosome organization during axon elongation.
abstract: Early endosomes are essential for regulating cell signalling and controlling the amount of cell surface molecules during neuronal morphogenesis. Early endosomes undergo retrograde transport (clustering) before their homotypic fusion. Small GTPase Rab5 is known to promote early endosomal fusion, but the mechanism linking the transport/clustering with Rab5 activity is unclear. Here we show that Drosophila Strip is a key regulator for neuronal morphogenesis. Strip knockdown disturbs the early endosome clustering, and Rab5-positive early endosomes become smaller and scattered. Strip genetically and biochemically interacts with both Glued (the regulator of dynein-dependent transport) and Sprint (the guanine nucleotide exchange factor for Rab5), suggesting that Strip is a molecular linker between retrograde transport and Rab5 activation. Overexpression of an active form of Rab5 in strip-mutant neurons suppresses the axon elongation defects. Thus, Strip acts as a molecular platform for the early endosome organization that has important roles in neuronal morphogenesis.
authors.affiliation: Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Chisako
authors.initials: C
authors.lastname: Sakuma
authors.affiliation: 1] Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan [2] PRESTO, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawauchi
authors.affiliation: Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Shuka
authors.initials: S
authors.lastname: Haraguchi
authors.affiliation: Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan.
authors.forename: Mima
authors.initials: M
authors.lastname: Shikanai
authors.affiliation: 1] Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] PRESTO, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Gelfand
authors.affiliation: Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.
authors.forename: Liqun
authors.initials: L
authors.lastname: Luo
authors.affiliation: 1] Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] CREST, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miura
authors.affiliation: 1] Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] PRESTO, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan [3] CREST, Japan Science and Technology Agency (JST), 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Chihara
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D011992:Endosomes / Q000235:genetics / Q000378:metabolism*; D009024:Morphogenesis; D055495:Neurogenesis; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors; C096359:sr protein, Drosophila