アラビドプシスのクロマチンを改変する核シRNA経路には,核核RNA処理センターが含まれています
Olga Pontes1, Carey Fei Li, Pedro Costa Nunes
1Biology Department, Washington University, 1 Brookings Drive, St. Louis, MO 63130, USA.
Cell
|July 15, 2006
まとめ
小型の干渉RNA (siRNAs) は,アラビドopsisのDNAメチル化を誘導する. RNAポリメラーゼIV (Pol IV),RNA依存性RNAポリメラーゼ2 (RDR2) およびARGONAUTE4 (AGO4) を含む主要なタンパク質は,このプロセスのために特定の細胞区間に局所化します.
科学分野:
- 植物分子生物学 植物分子生物学
- エピジェネティクス エピジェネティクス
- RNAの干渉によるRNA干渉
背景:
- アラビドプシス・タリアナのサイトシンメチレーションは,内生的なDNAの繰り返しを静止するために重要である.
- この表遺伝的プロセスは,RNAポリメラーゼ,Dicer型タンパク質,Argonaute型タンパク質を含む複雑な経路に依存しています.
研究 の 目的:
- siRNA誘導DNAメチル化に関与する主要なタンパク質の細胞下部位と作用の順序を調査する.
- アラビドプシスのRNA誘導DNAメチル化経路の空間的組織を解明する.
主な方法:
- 免疫光顕微鏡で,siRNAsと経路タンパク質のコロカライゼーションを視覚化します.
- タンパク質の作用の順序を決定するために,変異体におけるタンパク質の誤局の分析.
主要な成果:
- RNA依存型RNAポリメラーゼ2 (RDR2),DCER-LIKE3 (DCL3),ARGONAUTE4 (AGO4),およびPol IVbサブユニットNRPD1bは,核中のsiRNAとコロカライズする.
- RNAポリメラーゼIVa (Pol IVa) とDRD1は,内生的な繰り返しの場所において,核細胞の外部に局所する.
- Pol IVaは経路の上流で作用し,その局所化はRNAに依存しています.
結論:
- siRNA誘導メチル化経路は,siRNA複合体の核処理センターを持つ明確な空間的区画化を伴う.
- Pol IVaは,標的の位置で転写を開始し,その後,siRNAの生成と静音化複合体の組み立てが行われます.
- この空間的組織は,重複するDNA要素のヘテロクロマティック状態を維持するために重要である.
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