硫黄アミノ酸は,tRNAチオレーションの調節を通じて,翻訳能力と代謝恒常性を調節する
Sunil Laxman1, Benjamin M Sutter, Xi Wu
1Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9038, USA.
Cell
|July 23, 2013
まとめ
細胞内の硫黄アミノ酸レベルは,tRNAのチオレーションを制御し,これはタンパク質の翻訳と成長に不可欠な修正である. この発見は,代謝性ホメオスタシスと栄養素の変化への細胞適応の重要なメカニズムを明らかにしています.
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.
- 細胞の代謝について
背景:
- タンパク質翻訳は,栄養素の利用可能性に基づいて厳格な規制を必要とするエネルギー集約的なプロセスです.
- 振動性ウリジン (U34) のチオラ化のようなトランスファーRNA (tRNA) の改変は,特にストレス下では,細胞機能にとって不可欠です.
- 特定のtRNAs (ライシン,グルタミン,グルタミン酸) は,成長に関連するタンパク質で濃縮されたコドンの翻訳に関与しています.
研究 の 目的:
- 細胞内硫黄アミノ酸の利用可能性とtRNAのチオラ化状態の間の直接的な関係を調査する.
- 細胞の翻訳能力と代謝性ホメオスタシスの調節におけるtRNAチオレーションの役割を明らかにする.
- 硫黄の飢餓中に細胞が採用する適応メカニズムを理解するために.
主な方法:
- 細胞内メチオニンとシステイン濃度の分析.
- 特定のtRNA (ライシン,グルタミン,グルタミン酸) のtRNAチオレーション状態の評価.
- 細胞の翻訳能力と遺伝子発現の測定.
- アミノ酸生物合成を含む代謝経路の評価.
主要な成果:
- 細胞内メチオニンとシステインの利用性は,ライシン,グルタミン,グルタミン酸トRNAにおけるU34核酸のチオレーション状態を直接制御する.
- tRNAのチオレーションは,硫黄の飢餓の間にダウンレギュレーションされ,硫黄の消費と成長を減少させます.
- tRNAのチオレーションの欠如は,メチオニン,システイン,ライシンのバイオシンセシスの増加につながります.
- tRNAのチオレーションは,成長と翻訳に関与するタンパク質をコードする遺伝子の効率的な翻訳に不可欠です.
結論:
- tRNAチオレーションは,硫黄アミノ酸の可用性の重要なセンサおよびレギュレータとして作用し,翻訳能力を調節します.
- この保存されたtRNAの改変は,細胞の成長を制御し,代謝的恒常性を維持する上で重要な役割を果たします.
- 細胞は,トランスレーション機構を,変動する栄養条件,特に硫黄の利用可能性に適応させるために,tRNAチオラ化を利用する.
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Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
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