VDAC2はBAKの活性化とミトコンドリアアポトシスを阻害する
Emily H Y Cheng1, Tatiana V Sheiko, Jill K Fisher
1Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
まとめ
ミトコンドリア外膜タンパク質VDAC2は,不活性状態のプロアポプトティックタンパク質BAKを隔離する. VDAC2の異位はBAKを活性化し,アポトーシスを開始し,プログラム細胞死の主な調節体を明らかにします.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
背景:
- アポプトシスのミトコンドリア経路は,プロアポプトシスタンパク質であるBAKとBAXによって開始されます.
- 細胞がミトコンドリアでBAKを不活性なモノメール状態に維持するメカニズムは現在不明です.
研究 の 目的:
- ミトコンドリアにおけるBAKの非活性構成を調節するメカニズムを解明する.
- BAKの活性と相互作用し,制御するタンパク質を特定する.
主な方法:
- 同免疫プレシピテーションは,BAKと相互作用するタンパク質を特定するための測定法です.
- VDAC2欠乏細胞におけるBAKオリゴメリゼーションとアポプトシス感受性の分析.
- BAK活性化とアポトーシスへの影響を評価するためにVDAC2の過剰発現の研究.
主要な成果:
- BAKは,活性の高い細胞で,ミトコンドリア外膜タンパク質の低濃度であるVDAC2と複合していることが判明しました.
- VDAC2は,BAK.の非活性型と特異的に相互作用する.
- VDAC2に欠乏した細胞は,VDAC1に欠乏した細胞とは異なり,BAKのオリゴメリゼーションとアポトーシスの感受性が増加したことを示した.
- VDAC2の過剰発現は,BAKの活性化とミトコンドリアのアポプトシス経路を阻害した.
結論:
- VDAC2は,BAK活動の重要なレギュレータとして作用し,それを不活性状態に維持します.
- アポプトーシスの活性化には,BH3のみのタンパク質がBAKからVDAC2を位移させ,BAKのホモオリゴメリゼーションにつながります.
- VDAC2は,ミトコンドリア機能とコアアアポプトシス機構の間のリンクを提供します.
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