このエントリーをはてなブックマークに追加
ID 52344
フルテキストURL
著者
Masumoto, Toshio Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol
Suzuki, Koichiro Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol
Ohmori, Iori Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol
Michiue, Hiroyuki Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol Kaken ID
Tomizawa, Kazuhito Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol
Fujimura, Atsushi Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol
Nishiki, Tei-ichi Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol Kaken ID
Matsui, Hideki Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Physiol Kaken ID publons researchmap
抄録
Although synaptotagmin I, which is a calcium (Ca2+)-binding synaptic vesicle protein, may trigger soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated synaptic vesicle exocytosis, the mechanisms underlying the interaction between these proteins remain controversial, especially with respect to the identity of the protein(s) in the SNARE complex that bind(s) to synaptotagmin and whether Ca2+ is required for their highly effective binding. To address these questions, native proteins were solubilized, immunoprecipitated from rat brain extracts, and analyzed by immunoblotting. SNARE complexes comprising syntaxin 1, 25-kDa synaptosomal-associated protein (SNAP-25), and synaptobrevin 2 were coprecipitzted with synaptotagmin I in the presence of ethylene glycol tetraacetic acid. The amount of cop recipitated proteins was significantly unaltered by the addition of Ca2+ to the brain extract. To identify the component of the SNARE complex that bound to synaptotagmin, SNARE was coexpressed with synaptotagmin in HEK293 cells and immunoprecipitated. Syntaxin, but not SNAP-25 and synaptobrevin, bound to synaptotagmin in a Ca2+-independent manner, and the binding was abolished in the presence of 1 M NaCl. Synaptotagmin contains 2 Ca2+-binding domains (C(2)A, C2B). Mutating the positively charged lysine residues in the putative effector-binding region of the C2B domain, which are critical for transmitter release, markedly inhibited synaptotagmin-syntaxin binding, while similar mutations in the C(2)A domain had no effect on binding. Synaptotagmin-syntaxin binding was reduced by mutating multiple negatively charged glutamate residues in the amino-terminal half of the syntaxin SNARE motif. These results indicate that synaptotagmin I binds to syntaxin 1 electrostatically through its C2B domain effector region in a Ca2+-independent fashion, providing biochemical evidence that synaptotagmin I binds SNARE complexes before Ca2+ influx into presynaptic nerve terminals.
キーワード
Neurotransmitter release
Synaptic vesicle
Exocytosis
SNAP-25
Synaptobrevin
発行日
2012-01
出版物タイトル
Molecular and Cellular Neuroscience
49巻
1号
開始ページ
1
終了ページ
8
ISSN
1044-7431
資料タイプ
学術雑誌論文
オフィシャル URL
http://www.sciencedirect.com/science/article/pii/S1044743111002181
関連URL
http://ousar.lib.okayama-u.ac.jp/metadata/52246
言語
English
著作権者
(C) 2011 Elsevier Inc. All rights reserved.
論文のバージョン
author
査読
有り
DOI
Web of Science KeyUT