Synaptotagmin IV regulates dense core vesicle (DCV) release in LbetaT2 cells.
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.
Hu
Zhi-Tao
ZT
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.
Chen
Mao-Rong
MR
Ping
Zhao
Z
Dong
Yong-Ming
YM
Zhang
Rong-Ying
RY
Xu
Tao
T
Wu
Zheng-Xing
ZX
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*
D034741:RNA, Small Interfering; D050863:Synaptotagmin I; D050857:Synaptotagmins; D002118:Calcium