シナプトタグミンのC(2) B Ca(2+) 結合モチーフは,生体内におけるシナプス伝達のために必要である
J M Mackler1, J A Drummond, C A Loewen
1Department of Anatomy and Neurobiology, Program in Molecular, Cellular, and Integrative Neuroscience, Colorado State University, Fort Collins, Colorado 80523, USA.
Nature
|July 12, 2002
まとめ
シナプトタグミンは,
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
背景:
- シナプトタグミンは,シナプス胞の重要なタンパク質です.
- それは神経伝達物質の放出のためのカルシウム (Ca2+) センサーとして機能すると信じられています.
- シナプトタグミンの遺伝的消去は,シナプス伝播を著しく阻害する.
研究 の 目的:
- シナプトタグミンのCa2+結合部位がシナプス伝達のために必要であることを in vivoで調査する.
- シナプトタグミンのC2B領域内の特定のCa2+結合残留物が機能に不可欠であるかどうかを判断する.
主な方法:
- シナプトタグミンのC2B領域における保存された酸性残基のサイト指向型変異.
- 遺伝子組み換え生物 (ドロソフィラ) で誘発された神経伝達物質の放出の分析.
- シナプス伝達におけるCa2+近親性の評価.
主要な成果:
- C2Bドメインの2つのCa2+結合アスパルテート残留物 (D416,418N) の変異により,誘発されたトランスミッター放出が大幅に減少した (>95%).
- この変異はまた,誘発された放出の明らかなCa2+親和性を減少させた.
- C2BドメインのCa2+結合モチーフのインビボの必要性を実証した.
結論:
- シナプトタグミンのC2Bドメイン内のCa2+結合モチーフは,シナプス伝送に不可欠です.
- この研究は,シナプトタグミンの機能における特定のCa2+結合部位の役割に関する直接的なin vivo証拠を提供します.
- 神経伝達物質の放出を調節するシナプトタグミンのCa2+感知能力の重要性を強調しています.
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