title: Synaptotagmin IV regulates dense core vesicle (DCV) release in LbetaT2 cells.
abstract: Synaptotagmins (Syts) are calcium-binding proteins which are conserved from nematodes to humans. Fifteen Syts have been identified in mammalian species. Syt I is recognized as a Ca(2+) sensor for the synchronized release of synaptic vesicles in some types of neurons, but its role in the secretion of dense core vesicles (DCVs) remains unclear. The function of Syt IV is of particular interest because it is rapidly up-regulated by chronic depolarization and seizures. Using RNAi-mediated gene silencing, we have explored the role of Syt I and IV on secretion in a pituitary gonadotrope cell line. Downregulation of Syt IV clearly reduced Ca(2+)-triggered exocytosis of dense core vesicles (DCVs) in LbetaT2 cells. Syt I silencing, however, had no effect on vesicular release.
authors.affiliation: Key Laboratory of Molecular Biophysics, Ministry of Education, and Joint Laboratory of Institute of Biophysics & Huazhong University of Science and Technology, Huazhong University of Science and Technology, Luoyu Road 1037#, Wuhan 430074, PR China.
authors.forename: Zhi-Tao
authors.initials: ZT
authors.lastname: Hu
authors.forename: Mao-Rong
authors.initials: MR
authors.lastname: Chen
authors.forename: Zhao
authors.initials: Z
authors.lastname: Ping
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Dong
authors.forename: Rong-Ying
authors.initials: RY
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.forename: Zheng-Xing
authors.initials: ZX
authors.lastname: Wu
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002460:Cell Line; D015536:Down-Regulation; D005089:Exocytosis / Q000187:drug effects / Q000235:genetics; D051379:Mice; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology; D022142:Secretory Vesicles / Q000187:drug effects / Q000378:metabolism*; D050863:Synaptotagmin I / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D050857:Synaptotagmins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D034741:RNA, Small Interfering; D050863:Synaptotagmin I; D050857:Synaptotagmins; D002118:Calcium