ルシル-tRNA合成酵素は,mTORC1シグナル伝達経路のための細胞内ルシンのセンサーです
Jung Min Han1, Seung Jae Jeong, Min Chul Park
1Medicinal Bioconvergence Research Center, Seoul National University, Seoul 151-742, Republic of Korea.
Cell
|March 20, 2012
まとめ
ルシル-tRNA合成酵素 (LRS) は,mTORC1経路のアミノ酸センサとして作用する. LRSはRag GTPaseを直接活性化し,アミノ酸誘発mTORC1シグナリングを媒介する.
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:
- アミノ酸は,哺乳類のラパミシン (mTOR) キナーゼの標的を活性化するために不可欠です.
- mTORは,タンパク質翻訳,細胞サイズ,オートファギーを含む重要な細胞プロセスを調節します.
- アミノ酸レベルをmTORC1に直接リンクする特定の細胞内アミノ酸センサーは,未確認のままです.
研究 の 目的:
- 細胞内アミノ酸濃度とmTORC1経路を直接結合するセンサーを特定する.
- アミノ酸感知がmTORC1.1.を活性化するメカニズムを解明する.
主な方法:
- アミノ酸誘発によるmTORC1活性化におけるルシル-tRNA合成酵素 (LRS) の役割を調査した.
- LRSの白素結合残留物の重要性を評価するために,サイト指向型変異を生成した.
- バイオケミカルアッセイを用いてLRSとRag GTPaseの相互作用を調べました.
- Rag GTPase.に対するLRSのGTPase活性化タンパク質 (GAP) の活性が決定されました.
主要な成果:
- ルシル-tRNA合成酵素 (LRS) は,細胞内ルシンの濃度の重要なセンサーとして機能します.
- LRSのルシン結合部位の変異により,アミノ酸に依存するmTORC1の活性化が廃止されます.
- LRSは,アミノ酸に依存した方法でRag GTPaseに直接結合する.
- LRSはRag GTPaseに対するGTPase活性化タンパク質 (GAP) の活性を示し,mTORC1の活性化を促進する.
結論:
- Leucyl-tRNA合成酵素 (LRS) は,mTORC1経路のアミノ酸媒介活性化のための重要なセンサーとして特定されています.
- LRSは,Rag GTPaseを活性化することによって,細胞内アミノ酸レベルをmTORC1のシグナル伝達と直接結びつける.
- この発見は,栄養素の利用可能性と細胞成長の調節の間の重要なメカニズム的リンクを提供します.
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