ヒトのリソソームのmTORC1エスカフォルド複合体の結晶構造と信号伝達への影響
Mariana E G de Araujo1, Andreas Naschberger2, Barbara G Fürnrohr2
1Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria.
まとめ
LAMTOR複合体またはRagulatorは,リソソームのmTORC1活動を調節する. LAMTOR1はRag GTPasesの複合と安定化に不可欠であり,正確なmTORC1シグナリングを確保します.
科学分野:
- 細胞生物学
- 分子生物学
- 生物化学
背景:
- ラガムイシン複合体1 (mTORC1) の信号伝達のメカニズムのターゲットを調節するために,ラムトー (LAMTOR) 複合体 (遅いエンドソームおよびリソームアダプターおよびMAPKおよびmTORアクティベーター) が不可欠である.
- mTORC1の活動は主にライソソームで制御され,LAMTOR複合体はこの位置で重要な支柱として機能する.
研究 の 目的:
- LAMTOR複合体の構造的組織を解明する.
- ラグレーター複合体の組立と機能におけるLAMTOR1の役割を定義する.
- LAMTORがmTORC1の活性化のためにRag GTPasesを勧誘し,安定させるメカニズムを理解する.
主な方法:
- LAMTOR複合体の構造を決定するX線結晶学.
- LAMTOR1における重要なアミノ酸領域を特定するためのサイト指向型変異.
- 複合体の組立と機能を研究するための in vitro 溶解試験.
- GTPase結合とmTORC1シグナル伝達におけるLAMTOR1の役割を検証する機能試験.
主要な成果:
- 結晶構造は,LAMTOR複合体は,複合体をリソソームに固定するLAMTOR1によって安定した2つのヘテロダイマーによって形成されていることを示している.
- ラグGTPasesは,そのC端領域を通じてペンタメリックLAMTOR複合体と結合し,mTORC1の相互作用を誘導する.
- LAMTOR1は,複合体全体の組み立てとRag GTPasesの採用/安定化において重要な役割を果たしています.
結論:
- LAMTOR1はライソソーム上のラグレーター複合体の適切な組み立てに不可欠です.
- 構造的および機能的データは,Rag GTPaseの相互作用を媒介することによって,リソソームのmTORC1シグナル伝達の忠実性を確保するLAMTOR1の重要性を強調しています.
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