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Rループは,哺乳類の遺伝子ターミネーターの上に抑圧的なクロマチンの痕跡を誘発する
Konstantina Skourti-Stathaki1, Kinga Kamieniarz-Gdula1, Nicholas J Proudfoot1
1Sir William Dunn School of Pathology, South Parks Road, University of Oxford, Oxford OX1 3RE, UK.
Nature
|October 9, 2014
まとめ
R-ループ,DNA-RNAハイブリッドは,遺伝子終末部位で反意味転写を誘発する. これはRNAの干渉を誘発し,RNAポリメラーゼIIの停止を強化し,遺伝子終結を促進する抑制性ヒストンマークにつながります.
科学分野:
- 分子生物学は分子生物学である.
- エピジェネティクス エピジェネティクス
- 遺伝子規制 遺伝子規制
背景:
- R-ループは,転写中に形成されたDNA-RNAハイブリッドです.
- 以前はトランスクリプションの副産物と考えられていたRループは,現在,規制的な役割を持つことが知られている.
- R-ループは,Gに富んだターミネーター要素で濃縮され,RNAポリメラーゼIIの一時停止に影響を与えます.
研究 の 目的:
- 遺伝子終末部位におけるRループの機能的役割を調査する.
- Rループと表遺伝的変異と転写終結を結びつけるメカニズムを解明する.
主な方法:
- Rループ形成と関連する表遺伝子マークの分析.
- RNA干渉経路成分 (DICER,AGOs) の役割を調査する.
- RNAポリメラーゼIIの停止と遺伝子終結への影響を研究する.
主要な成果:
- Rループは,パウズ要素で反意味転写を誘導する.
- アンチセンセスのトランスクリプトは二重鎖RNAを生成し,DICERとAGOタンパク質を勧誘する.
- これにより,H3K9me2の堆積とHP1γの徴集が起こり,Pol IIの停止が強化されます.
結論:
- R-ループは,終端領域でRNA干渉依存のH3K9me2形成を促進する.
- Rループは,遺伝子の終末部位を定義する染色体構造に寄与する.
- このメカニズムは,哺乳類のタンパク質をコードする遺伝子の転写終止を調節する.
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