RNAポリメラーゼIは,rDNAサイレントクロマチンの一方的な拡散を伝播する
Stephen W Buck1, Joseph J Sandmeier, Jeffrey S Smith
1Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, USA.
Cell
|January 1, 2003
まとめ
イーストでは,リボソームDNA (rDNA) サイレンシングは方向的に広がり,RNAポリメラーゼIトランスクリプションとSIR2.2を必要とします. このプロセスは再結合を制限し,寿命に影響を与えます.
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
- エピジェネティクス エピジェネティクス
背景:
- Saccharomyces cerevisiaeのリボソームDNA (rDNA) は,RNAポリメラーゼII遺伝子の転写サイレンシングを誘発することが知られている.
- このSIR2依存抑制 (rDNAサイレンシング) は,rDNA再結合を制限し,寿命を調節するために極めて重要です.
研究 の 目的:
- イーストにおけるrDNAサイレンシングの拡散ダイナミクスと規制メカニズムを調査する.
- rDNAサイレンシングの確立と方向性におけるRNAポリメラーゼI (Pol I) 転写の役割を決定する.
主な方法:
- 遺伝子の静止と隣接するユニークな配列に広がる分析.
- SIR2活性と相関するヒストン脱酸化 (H3およびH4) のモニタリング.
- SIR2過剰発現がサイレンシングの拡散に及ぼす影響を調査する.
- rDNAサイレンシングのためのPol Iトランスクリプションの必要性を評価する.
主要な成果:
- rDNAサイレンシングは,Pol Iトランスクリプションの下流のセントロメア-近隣のユニークな配列に広がりますが,上流のテロメア-近隣の配列に広がることはありません.
- 静止拡散は,SIR2依存ヒストーンH3およびH4の脱酸化と関連しており,SIR2過剰発現によって強化される可能性があります.
- rDNAサイレンシングはPol Iトランスクリプションに依存し,その拡散の方向はPol Iトランスクリプションの方向によって決定されます.
結論:
- Pol Iトランスクリプションは,rDNAサイレンシングの拡散の方向性を確立する上で重要な役割を果たします.
- この発見は,Pol Iトランスクリプションが表遺伝的サイレンシングの境界を決定し,rDNAの安定性と寿命に影響を与える新しいメカニズムを明らかにしています.
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