クロマチンのドッキングと交換活動強化は,ヒストンH2AとH2BによるRCC1の強化です

M E Nemergut¹, C A Mizzen, T Stukenberg

¹Center for Cell Signaling, University of Virginia, Charlottesville, VA 22908, USA. men5w@virginia.edu

Science (New York, N.Y.)

|May 26, 2001

まとめ

染色体凝縮1の調節体 (RCC1) は,ヒストンH2AとH2Bに直接結合し,その活動を刺激する. クロマチンとのこの相互作用は,核細胞プラズマ輸送と核封筒組成の鍵です.

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
バイオケミストリーバイオケミストリー

背景:

ランGTPアゼは,核サイトプラズマ輸送,ミトーシススパインドル形成,核封筒組立に不可欠です.
これらの細胞プロセスは,染色体凝縮1 (RCC1) の調節体であるRan特異的交換因子 (Ran-specific exchange factor) に依存し,染色素と関連しています.

研究の目的:

RCC1がクロマチンと結合する分子メカニズムを調査する.
RCC1-クロマチンの相互作用が,その触媒活動と下流の細胞機能にどのように影響するか解明する.

主な方法:

バイオケミカルアッセイは,RCC1が核細胞とヒストンに直接結合することを決定する.
クロマチンの結合測定は,Xenopusの精子のクロマチンを用いたものです.
酵素活性アッセイは,ヒストン結合時のRCC1触媒活性を測定する.

主要な成果:

RCC1は,モノヌクレオソーム,特にヒストンH2AとH2Bに直接結合する.
RCC1はH2A/H2Bを利用して,Xenopusの精子クロマチンを結合する.
RCC1が核個体やヒストンに結合すると,RCC1の触媒活性が著しく刺激されます.

結論:

RCC1のヒストンH2A/H2Bとの相互作用は,その染色体関連性の主要なメカニズムである.
このヒストン媒介結合はRCC1の活性を増大させ,核封筒の組立と輸送に必要なRan-GTPグラデントを確立する可能性が高い.
この発見は,クロマチンの構造と基本的な核事象の調節の間のメカニズム的なリンクを提供する.

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