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TORは,PKAとフォークヘッド転写因子FHL1を介してリボソームタンパク質の遺伝子発現を調節する
Dietmar E Martin1, Alexandre Soulard, Michael N Hall
1Division of Biochemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.
Cell
|December 29, 2004
まとめ
ラパミシン (TOR) 経路の標的は,タンパク質キナーゼA (PKA) を通してリボソーム生体生成を調節する. この研究では,フォークヘッド型転写因子1 (FHL1) およびその共因子IFH1およびCRF1が,この栄養素に敏感なシグナル伝達メカニズムにおいて重要な役割を果たしていることを特定しています.
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:
- リボソーム生物生成は細胞成長に不可欠であり,環境のシグナルによって厳しく規制されています.
- ラパミシン (TOR) 信号伝達経路の栄養素に敏感な標的は,細胞成長の中心的な調節因子である.
- TORはタンパク質キナーゼA (PKA) の局所化に影響しますが,リボソームタンパク質 (RP) の遺伝子調節のための下流転写因子は未確認のままです.
研究 の 目的:
- 酵母におけるTOR-PKA経路によるRP遺伝子調節を媒介する転写因子の解明.
- 環境感知とリボソーム生物発生制御を結びつけるシグナリングメカニズムを明らかにする.
主な方法:
- イースト遺伝学と分子生物学技術.
- 転写因子の局所化と活性に関する分析.
- RP遺伝子プロモーターにおけるタンパク質-タンパク質相互作用の調査.
主要な成果:
- フォークヘッド型の転写因子FHL1は,共活性化因子IFH1とコアプレッサーCRF1とともに,TOR/PKA媒介のRP遺伝子転写に不可欠である.
- PKA経由のTORシグナル伝達は,YAK1キナーゼの活性を抑制し,CRF1を細胞質に保持する.
- TORの無活性化により,YAK1の活性化,CRF1のリン酸化,核の蓄積,そしてその後,IFH1とFHL1結合の競争によってRP遺伝子転写の抑制が生じます.
結論:
- 新しいシグナル伝達経路が記述され,TOR/PKA経由で環境感知をリボソーム生物発生の調節と結びつける.
- FHL1,IFH1,CRF1,YAK1の相互作用は,栄養素の利用可能性に応じてRP遺伝子発現を制御するメカニズムを提供します.
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Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
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