フォトアフィニティタンパク質-リガンドラベル方式によるサイクルアデノシン二酸化塩素結合タンパク質としてのグリセラルデヒド3酸塩脱水酵素の識別
Kehui Zhang1,2, Wei Sun2,3, Lihong Huang2
1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University , Beijing 100191, China.
Journal of the American Chemical Society
|December 13, 2016
まとめ
グリセラルデヒド3酸塩脱水酵素 (GAPDH) はサイクルアデノシン二酸化塩素 (cADPR) に結合し,そのカルシウム放出機能を媒介する. この研究では,GAPDHがcADPRとライアノジン受容体によるカルシウム動員との間の重要なリンクであると特定されています.
科学分野:
- 細胞生物学
- 生物化学
- 分子信号
背景:
- 循環性アデノシンジフォリボース (cADPR) は,ニコチナミドアデニンジヌクレオチド (NAD+) から派生した重要な細胞内カルシウム調節剤である.
- リアノジン受容体 (RyRs) 経由で内プラズマ網膜 (ER) からのカルシウム放出とcADPRを結びつける正確な分子機構とタンパク質中間体は,未だに不明である.
- これらの相互作用を理解することは,細胞のカルシウムホメオスタシスとシグナル伝達経路の解読に不可欠です.
研究 の 目的:
- cADPRと結合し,そのカルシウム活性を媒介するタンパク質を特定する.
- cADPR とその結合タンパク質の相互作用を特徴づける.
- cADPR媒介によるカルシウム放出における特定されたタンパク質の役割を解明する.
主な方法:
- タンパク質の識別のための新しい光親和標識 (PAL) cADPRアゴニスト (PAL-cIDPRE) の合成.
- 人間のJurkat T細胞からのcADPR結合タンパク質のアフィニティ浄化
- 表面プラズモン共鳴 (SPR) 測定は,結合運動と親和性を特徴づけるためのものです.
- タンパク質の相互作用と機能的影響を評価するための in vivo および in vitro 実験.
主要な成果:
- グリセラルデヒド3リン酸脱水酵素 (GAPDH) は,cADPRの直接結合タンパク質として特定されました.
- SPR分析では,cADPRとGAPDHの間の高親和結合が確認され,特定の結合部位はGAPDHにマッピングされています.
- cADPRは,GAPDHとRyRsの間の一時的な相互作用をインビオで誘導し,GAPDHのノックダウンはcADPR誘発カルシウム放出を無効化しました.
結論:
- GAPDHは長い間求められてきた cADPRを結合するタンパク質です
- GAPDHは,cADPR誘発による ERから RyRへのカルシウム (Ca2+) 移動を媒介するために不可欠です.
- この発見は,細胞内カルシウムシグナル伝達におけるGAPDHの新たな役割を確立しています.
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