アンドロスタンの代謝産物は,CAR-β核受容体と結合し,それを無効化する
B M Forman1, I Tzameli, H S Choi
1The City of Hope National Medical Center, Duarte, California 91010, USA. bforman@gte.net
Nature
|October 23, 1998
まとめ
構成的なアンドロスターン受容体-β (CAR-β) の活動は,特定のアンドロスターンステロイドによって抑制されます. これらのステロイドは逆アゴニストとして作用し,CAR-βを逆転させます.
科学分野:
- 分子内分泌学分子内分泌学
- ステロイドシグナル伝達経路
- 核受容体研究について
背景:
- 孤児受容体CAR-β (構成的なアンドロスタネ受容体β) は,レチノイドX受容体と異体体を形成する.
- CAR-βは,リガンド結合とは独立して基因転写を構成的に活性化します.
- 古典的な核受容体は,通常,転写活性化のためにリガンド結合を必要とします.
研究 の 目的:
- CAR-βの構成活動の背後にあるメカニズムを調査する.
- CAR-β活性を調節する潜在的なリガンドを特定する.
- 特定されたリガンドの性質とその作用機構を特徴付ける.
主な方法:
- CAR-βの潜在的なリガンドのスクリーニング.
- 特定されたステロイドがCAR-βの構成的転写活動に及ぼす影響を評価する.
- ステロイド相互作用のステレオ特異性を評価する.
- ステロイドがCAR-βヘテロダイメリゼーション,DNA結合,コアクティベーターの募集/放出に及ぼす影響を分析する.
主要な成果:
- アンドロスタノールとアンドロステノールは,CAR-βの構成活性抑制剤として特定されました.
- 抑制効果はステレオ特異的であり,3α-ヒドロキシ,5α-減少アンドロスタンの構造を必要とする.
- これらのアンドロスタンは,ヘテロディメリゼーションやDNA結合に影響を与えないが,CAR-βからコアクティベーターの放出を促進する.
結論:
- CAR-βは,リガンド独立コアクティベーター募集によって機能する.
- 特定のアンドロスタンは,自然に存在するCAR-βの逆アゴニストとして作用する.
- これは,従来の核受容体メカニズムに反対する新しいステロイド信号伝達経路を定義します.
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