合成ヘテロクロマチンはRNAiとセントロメリックの繰り返しをバイパスして,機能的なセントロメアを確立します
Alexander Kagansky1, Hernan Diego Folco, Ricardo Almeida
1Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, 6.34 Swann Building, Edinburgh EH9 3JR, Scotland, UK.
Science (New York, N.Y.)
|June 27, 2009
まとめ
ヒストンH3ライシン9メチル化によって導かれるヘテロクロマチン形成は,分裂酵母における機能的セントロメアとキネトコア組成の確立に十分である. これは,RNAの干渉 (RNAi) や外部の繰り返しがなくても起こります.
科学分野:
- エピジェネティクス エピジェネティクス
- 分子生物学は分子生物学である.
- クロマチン生物学 クロマチン生物学
背景:
- 分裂酵母センターロメアは,CENP-A(Cnp1) ヌクレオソームにキネトコアを組み立てます.
- RNAの干渉 (RNAi) とヒストンH3リシン9メチルトランスフェラーゼClr4によって導かれるヘテロクロマチンの形成は,CENP-A(Cnp1) のクロマチンの確立に極めて重要です.
研究 の 目的:
- ヘテロクロマチンの形成だけではセントロメア形成に十分であるかどうかを調査する.
- ヘテロクロマチン形成を誘導する際の外部リピートとRNAiの役割を決定する.
主な方法:
- 合成ヘテロクロマチンを誘導するためにDNA結合部位を使用して,ユークロマティックロシにClr4を結合する.
- プラズミドベースのミニクロモソームの de novo CENP-A (((Cnp1) とキネトコアアセンブリの評価.
- アクティブRNAiの有無によるミトス分離の評価.
主要な成果:
- 結合されたClr4は,活性RNAiから独立して,ヘテロクロマチンアセンブリを成功裏に誘導した.
- 合成ヘテロクロマチンは,外部の繰り返しを代用し,新しいCENP-A (((Cnp1) とキネトコア組立を可能にします.
- 機能的なセントロメアとミトーシス分離は,RNAiが不活性であった場合でも達成されました.
結論:
- 外側の繰り返しは,主にヘテロクロマチン形成を誘導するRNAi基板である.
- H3K9メチル化に依存するヘテロクロマチンは,機能的なセントロメアとキネトコアを確立するのに十分です.
- セントロメア確立は,カノニカルRNAi経路とは独立して達成できます.
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