遺伝子発現におけるアクティベーターのターンオーバーに対する推定的な刺激作用
J Russell Lipford1, Geoffrey T Smith, Yong Chi
1Howard Hughes Medical Institute, Division of Biology, MC 156-29, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California 91125, USA.
Nature
|November 4, 2005
まとめ
ユビキチン-プロテアソームシステム (UPS) は,転写活性化剤を分解しますが,このタンパク質解離は逆説的に遺伝子発現を高めることができます. プロテアソームを阻害すると,Gcn4.4のような重要な酵母活性化剤の機能が損なわれます.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
背景:
- ウビキチン-プロテアソーム系 (UPS) は,タンパク質のレベルを調節し,細胞のプロセスに影響を与えます.
- 転写活性化剤は,遺伝子発現の重要な決定因子である.
- 転写調節におけるUPSの役割は複雑で,非プロテオリート機能の証拠が浮上しています.
研究 の 目的:
- 誘導可能な転写活性化剤の機能を刺激するUPS依存型タンパク質分解の役割を調査する.
- 特定のアクティベーターのタンパク質分解が,それらの転写活性を増強するかどうかを決定する.
主な方法:
- 転写活性化剤Gcn4,Gal4,Ino2/4.4の機能を研究するために酵母モデルを使用しました.
- 採用されたプロテアソーム阻害と,ユビキチンリガゼ (SCF ((Cdc4)) とユビキチンにおける特定の変異.
- 標的遺伝子転写とRNAポリメラーゼII関連への影響を評価した.
主要な成果:
- プロテアソーム阻害は,Gcn4,Gal4,およびIno2/4.4に対する標的の転写を低下させた.
- Gcn4のユビキチン化と分解に影響する突然変異は,標的遺伝子の転写を損なう.
- 転写欠陥は,Gcn4の豊富度が増加したにもかかわらず発生し,RNAポリメラーゼII関連が減少しました.
結論:
- UPSによる特定の転写活性化剤のタンパク質分解は,それらの機能を刺激することができます.
- UPSに依存する分解は,酵母における誘導可能な転写活性化剤の適切な活性化に不可欠である.
- 単なる多量ではなく,標的の分解がアクティベーター機能にとって重要である.
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