Sp1による転写活性化のメカニズム:コアクティベーターの証拠
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Cell
|June 29, 1990
まとめ
転写因子Sp1の活性化には,部分的に浄化されたTFIIDに存在するが,浄化されたTFIIDには存在しないコアクティベーターが必要です. これらのコアクティベーターは,Sp1と転写機構の間のアダプターとして機能します.
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
- バイオケミストリー バイオケミストリー
背景:
- トランスクリプションの開始は,多数のタンパク質因子を含む複雑なプロセスです.
- TFIID (転写因子II D) は,TATAボックスと結合し,転写を開始する重要な一般的な転写因子です.
- コアクティベーターは,転写を促進するタンパク質ですが,DNAを直接結合しません.
研究 の 目的:
- Sp1媒介による転写活性化におけるコアクティベーターの役割を調査する.
- 同活性化剤がTFIIDの重要な構成要素なのか,それとも別々の構成要素なのかを判断する.
- コアクティベーター-TFIID相互作用の種特異性を調査する.
主な方法:
- 部分的に浄化されたおよび浄化されたTFIID分子を用いた再構成された転写アッセイ.
- Sp1 (特定の転写因子) とCTF (コアクティベーター) による実験.
- 異なる種 (ドロソフィラ菌と酵母菌) からクローン化されたTFIIDタンパク質を用いて.
主要な成果:
- Sp1は,半浄化されたTFIIDでTATAを含むプロモーターからの転写を活性化しますが,浄化されたTFIIDではそうではありません.
- 部分的に精製されたTFIID分子は,Sp1-媒介活性化に不可欠な共活性化物質を含んでいます.
- コアクティベーターは,TFIIDのアミノ端末部分と相互作用し,これらの相互作用は種特有である.
- TATA-less プロモーターでの Sp1 活性化には,コアクティベーターとは別々の別々の活性が必要である.
結論:
- Sp1のようなトランスアクティベーターと一般的な転写機構の間の分子アダプターとして,コアクティベーターが必要です.
- これらのコアクティベーターは,TFIID自体とは異なるもので,基礎転写には欠かせない.
- コアクティベーター-TFIIDの相互作用は,種特異性を示し,異なる生物間の転写調節の複雑さを強調しています.
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