title: Local endocytosis triggers dendritic thinning and pruning in Drosophila sensory neurons.
abstract: The refinement of neural circuits involves dendrite pruning, a process that removes inappropriate projections that are formed during development. In Drosophila sensory neurons, compartmentalized calcium (Ca(2+)) transients in dendrites act as spatiotemporal cues to trigger pruning, yet how neurons define the dendrites with Ca(2+) transients remains elusive. Here we report that local elevation of endocytic activity contributes to defining dendrites that generate Ca(2+) transients, triggering pruning. In vivo imaging of single dendrites reveals an increase of endocytosis in proximal dendrites that spatially and temporally correlates with dendrite thinning, an early step in pruning tightly coupled with compartmentalized Ca(2+) transients. Two GTPases, Rab5 and dynamin, are required for both the increased endocytic activity and compartmentalized Ca(2+) transients. Further genetic analyses suggest that local endocytosis in proximal dendrites functions cooperatively with global endocytosis-mediated protein degradation pathways to promote dendrite pruning.
authors.affiliation: 1] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Cell Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0872, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kanamori
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Yoshino
authors.affiliation: 1] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Cell Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0872, Japan.
authors.forename: Kei-Ichiro
authors.initials: K
authors.lastname: Yasunaga
authors.affiliation: 1] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Cell Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0872, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Dairyo
authors.affiliation: 1] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan [2] Department of Cell Biology, Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0872, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Emoto
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002451:Cell Compartmentation; D003712:Dendrites / Q000378:metabolism* / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D034281:Dynamins / Q000235:genetics* / Q000378:metabolism; D004705:Endocytosis / Q000235:genetics*; D011992:Endosomes / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008675:Metamorphosis, Biological / Q000235:genetics; D057054:Molecular Imaging; D009473:Neuronal Plasticity / Q000235:genetics*; D059748:Proteolysis; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000648:ultrastructure; D020696:rab5 GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C586289:Rab5 protein, Drosophila; D020696:rab5 GTP-Binding Proteins; D034281:Dynamins; C439628:shi protein, Drosophila; D002118:Calcium