SIRT5はカルバモイルリン酸合成酵素1をデアセチル化し,尿素循環を調節する
Takashi Nakagawa1, David J Lomb, Marcia C Haigis
1Department of Biology, Massachusetts Institute of Technology, Cambridge, 02139, USA.
Cell
|May 5, 2009
まとめ
Sirtuin 5 (SIRT5) は,ミトコンドリア内のカルバモイルリン酸合成酵素1 (CPS1) を活性化させ,アンモニアの解毒に不可欠です. SIRT5欠乏症は,このプロセスを阻害し,断食や食事の変化でアンモニア濃度が上昇します.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- メタボリック・レギュレーション
背景:
- サーチューインは,代謝と老化を結びつけるNAD依存型脱酸化酵素である.
- 哺乳類のサートゥイン (SIRT1-7) には,ミトコンドリアと非ミトコンドリアのメンバーが含まれています.
- ミトコンドリアシルトゥインは,細胞のエネルギーホメオスタシスにおいて重要な役割を果たします.
研究 の 目的:
- ミトコンドリア機能と代謝適応におけるSIRT5の役割を調査する.
- 肝臓におけるSIRT5の基板と調節機構を特定する.
- アンモニアの解毒経路に対するSIRT5の貢献を明らかにする.
主な方法:
- ミトコンドリアタンパク質の局所化に関する研究.
- CPS1.の酵素活性アッセイ.
- 生化学的方法を用いたサーチューイン-基板相互作用分析.
- 様々な食事条件 (断食,カロリー制限,高タンパク質食事) の下でSIRT5ノックアウト (KO) マウスモデルを分析した.
主要な成果:
- SIRT5はミトコンドリアマトリックスに局所化し,CPS1.1と相互作用する.
- SIRT5は,重要な尿素循環酵素であるCPS1の活性を脱酸化し,上調する.
- CPS1のSIRT5の活性化は,断食中にミトコンドリアのNAD+が増加すると引き起こされます.
- SIRT5 KOマウスは,CPS1の活性が低下し,断食,カロリー制限,または高タンパク質の食事中に血中アンモニア濃度の上昇を示します.
結論:
- SIRT5はCPS1の活性とアンモニアの解毒の重要なレギュラーである.
- SIRT5は,尿素循環を調節することにより,栄養素の利用可能性に対する代謝適応を促進します.
- SIRT5の調節不良はアンモニアのホメオスタシスに影響し,代謝健康におけるその重要性を強調しています.
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