RARアルファ活性化機能AF-1の刺激は,一般転写因子TFIIHと結合し,CDK7によるリン酸化によって行われる
C Rochette-Egly1, S Adam, M Rossignol
1Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université Louis Pasteur, Collège de France, Illkirch, Strasbourg.
Cell
|July 11, 1997
まとめ
レチノイド酸受容体α (RARα) の活性度は,Ser-77のリン酸化に依存する. サイクリン依存キナーゼ7 (CDK7) と転写因子TFIIHはRARααを結合し,リン酸化し,トランザクティベーション機能を強化する.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝子規制 遺伝子規制
- タンパク質のリン酸化.
背景:
- レチノ酸受容体α (RARα) のN端の活性化機能AF-1は,その活性化に極めて重要です.
- Ser-77のような特定の残基のリン酸化は,RARαの機能を調節することができます.
研究 の 目的:
- RARアルファトランザクティベーションにおけるSer-77リン酸化の役割を調査する.
- セル-77のリン酸化に起因するキナーゼをインビヴォおよびインビトロで特定する.
- RARアルファと一般的な転写因子の相互作用を探求する.
主な方法:
- サイト・ディレクテッド・ミュータゲネシスにより,S77A RAR変異体が生成される.
- 再結合RARアルファおよび様々なキナーゼを用いたインビトロリン酸化アッセイ.
- セル-77のリン酸化とトランザクティベーションにcdk7の影響を評価するためのインビヴォ共発性研究.
- CAKとTFIIHへのRARアルファ結合を検出するための共免疫プレシピテーション.
主要な成果:
- Ser-77の変異により,RARアルファAF-1の活性が取り消された.
- CDK7共発現は,Ser-77のリン酸化とRARαのトランザクティベーションを in vivoで強化した.
- 自由なCDK活性化キナーゼ (CAK) とTFIIHリン酸化セル-77の両方 in vitro.
- RARアルファは,CAKとTFIIHに直接結合する.
結論:
- CDK7によるSer-77のリン酸化は,RARαトランザクティベーションに不可欠である.
- RARαは,一般的な転写因子TFIIHと相互作用する.
- この研究は,一般の転写因子による結合とリン酸化によるトランスアクティベーター活性化が初めて実証されました.
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