title: The role of VAMP7/TI-VAMP in cell polarity and lysosomal exocytosis in vivo.
abstract: VAMP7 or tetanus neurotoxin-insensitive vesicle- associated membrane protein (TI-VAMP) has been proposed to regulate apical transport in polarized epithelial cells, axonal transport in neurons and lysosomal exocytosis. To investigate the function of VAMP7 in vivo, we generated VAMP7 knockout mice. Here, we show that VAMP7 knockout mice are indistinguishable from control mice and display a similar localization of apical proteins in the kidney and small intestine and a similar localization of axonal proteins in the nervous system. Neurite outgrowth of cultured mutant hippocampal neurons was reduced in mutant neurons. However, lysosomal exocytosis was not affected in mutant fibroblasts. Our results show that VAMP7 is required in neurons to extend axons to the full extent. However, VAMP7 does not seem to be required for epithelial cell polarity and lysosomal exocytosis.
authors: Department of Cellular and Molecular Biology, Laboratory for Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan.
authors: Mahito
authors: M
authors: Sato
authors: Shinichiro
authors: S
authors: Yoshimura
authors: Rika
authors: R
authors: Hirai
authors: Ayako
authors: A
authors: Goto
authors: Masataka
authors: M
authors: Kunii
authors: Nur
authors: N
authors: Atik
authors: Takashi
authors: T
authors: Sato
authors: Ken
authors: K
authors: Sato
authors: Reiko
authors: R
authors: Harada
authors: Junko
authors: J
authors: Shimada
authors: Toshimitsu
authors: T
authors: Hatabu
authors: Hiroshi
authors: H
authors: Yorifuji
authors: Akihiro
authors: A
authors: Harada
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure; D015153:Blotting, Western; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D016764:Cell Polarity / Q000502:physiology*; D002478:Cells, Cultured; D005089:Exocytosis / Q000502:physiology*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D005753:Gastric Mucosa / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D008666:Metalloendopeptidases / Q000494:pharmacology*; D051379:Mice; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D050683:R-SNARE Proteins / Q000235:genetics / Q000502:physiology*; D013270:Stomach / Q000187:drug effects / Q000648:ultrastructure; D013744:Tetanus Toxin / Q000494:pharmacology*
chemical_list: D050683:R-SNARE Proteins; C496927:Sybl1 protein, mouse; D013744:Tetanus Toxin; C035979:tetanospasmin; D008666:Metalloendopeptidases