最初の亜鉛指の足首にある2つのアミノ酸は,グルココルチコイド受容体によるDNA応答要素の活性化を規定する
M Danielsen1, L Hinck, G M Ringold
1Department of Pharmacology, Stanford University School of Medicine, California 94305.
Cell
|June 30, 1989
まとめ
ステロイド受容体の特定のアミノ酸は,標的遺伝子の活性化を決定する. 最初の亜鉛指のわずかな変化により,受容体は異なるDNA応答要素に結合し,遺伝子調節の重要なメカニズムを明らかにします.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- バイオケミストリー バイオケミストリー
背景:
- ステロイド受容体は,特定のDNA配列を通して遺伝子発現を調節する.
- 2本の亜鉛指を形成するDNA結合ドメインは,この特異性にとって極めて重要です.
- 標的遺伝子の認識を決定する正確な構造要素は,まだ完全に理解されていません.
研究 の 目的:
- グルココルチコイド受容体 (GR) とエストロゲン受容体 (ER) のDNA結合特異性に関与する特定のアミノ酸残基を特定する.
- 密接に関連したホルモン反応要素 (HREs) の区別における最初の亜鉛指の役割を調査する.
- DNA結合ドメインの構造変化が受容体機能とHRE認識にどのように影響するか調査する.
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,キメリックなGRとERの構造が生成される.
- レポーター遺伝子解析は,GREおよびEREを含むプロモーターからの転写活性化を測定する.
- DNA結合ドメインの構造と機能の分析.
主要な成果:
- ステロイド受容体の最初の亜鉛指内の2つの特定のアミノ酸は,その同類の反応要素を区別するために重要である.
- 最初の指のドメインが変化したキメリック受容体は,変化したDNA結合特異性を示した.
- 最初の指の"指関節"領域の変更は,シーケンス認識に大きく影響しました.
結論:
- 最初の亜鉛指で特定されたアミノ酸は,ステロイド受容体のDNA結合特異性の主要な決定因子です.
- より広範なDNA結合領域は,非特異的なDNA相互作用を防ぐために不可欠な構造的文脈を提供します.
- これらの発見は,ステロイドホルモンによる選択的遺伝子活性化の基礎となる分子機構の洞察を提供します.
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