人間のTRPM2の構造とゲートメカニズム
Longfei Wang1,2, Tian-Min Fu3,2, Yiming Zhou4,5
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
まとめ
この研究では,カルシウム (Ca2+) とアデノシン・ディフォスファート (ADP) - リボース (ADPR) がTRPM2チャネルを活性化する方法が明らかになりました. 構造的な洞察は,Ca2+とADPRの結合が構造変化を引き起こし,チャネル孔を開くことを示しています.
科学分野:
- 分子生物学
- 構造生物学
- 生物化学
背景:
- トランジエント受容体ポテンシャル (TRP) メラスタチン2 (TRPM2) は,様々な疾患に関与する重要なカチオンチャネルである.
- TRPM2の活性化は,アデノシン二酸化物 (ADP) - リボース (ADPR) がそのC端のNUDT9ホモロジー領域 (NUDT9H) に結合し,カルシウム (Ca2+) の存在に依存する.
研究 の 目的:
- ADPRとCa2+によるTRPM2チャネルゲートの分子メカニズムを解明する.
- TRPM2の活性化プロセスに関する構造的な洞察を提供するためです.
主な方法:
- ヒトのTRPM2の構造を決定するために,冷凍電子顕微鏡 (cryo-EM) が使用されました.
- ADPRと結合し,ADPRとCa2+の両方に結合したアポ状態のTRPM2の構造が得られました.
主要な成果:
- NUDT9Hドメインは,アポ状態のN端TRPMホモロジー領域 (MHR1/ 2/ 3) と相互作用する.
- ADPR結合は,MHR1/ 2の回転とサブユニット間の相互作用の障害を含む構造変化を誘導する.
- Ca2+結合は,トランスメブランヘリックスとTRPヘリクスをさらに安定させ,毛穴を開けます.
結論:
- この研究は,ADPRとCa2+によるTRPM2の協調されたゲートの詳細な分子説明を提供します.
- これらの発見は,他のTRPチャネルのゲートメカニズムに関する貴重な洞察を提供します.
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