関連する実験動画
Updated: May 10, 2026

07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 30, 2010
レプリコンのダイナミクス,ドーパント・オリジンの発火,そしてダブル・ストランド・ブレイク・フォーキング形成後の端末フォークの整合性
Ylli Doksani1, Rodrigo Bermejo, Simona Fiorani
1FIRC Institute of Molecular Oncology Foundation (IFOM-IEO Campus) and DSBB-Università degli Studi di Milano, Via Adamello 16, 20139 Milan, Italy.
Cell
|April 14, 2009
まとめ
DNAの二重鎖断裂 (DSB) は,複製フォークを切り離し,不活性な起源発射または隣接複製を誘発し,ゲノム安定性を確保することができます. この研究では,Mre11-Tel1/ATM経路がS段階のターミナルフォークの完全性にとって重要なことを明らかにしました.
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
- 遺伝学 遺伝学とは
背景:
- 複製のストレスは, Mec1/ATRとSUMO経路を活性化し,停滞や損傷したフォークの安定性を確保します.
- DNAの破裂に対するS相反応を理解することは,ゲノムの安定性にとって極めて重要です.
研究 の 目的:
- 破壊されたDNAテンプレート (ターミナルフォーク) に遭遇する複製フォークのS相応答を調査する.
- 端末フォークの整合性を制御するメカニズムと,ダブルストランドブレイク (DSB) 形成後の姉妹フォークの進行を明らかにする.
主な方法:
- 複製フォークのダイナミクスとDNA修復経路を研究するために酵母モデルを使用しました.
- Mre11,Tel1/ATM,Mec1/ATR,およびSUMO経路のDSBへの反応における役割を分析した.
主要な成果:
- DSBの形成は,局所的に休眠原発発射を誘発する可能性があります.
- 端末フォークの不可逆的な解像度は,姉妹フォークの進行を停止しません.
- Mre11-Tel1/ATM経路は,末端フォークの異常DNA構造を防止し,姉妹染色体の完全性を維持します.
結論:
- 姉妹複製フォークは,DNA複製中に分離することができます.
- 複製は,DSB誘発のフォーク終了後の休眠起源または隣接する複製によって救出することができます.
- Mre11-Tel1/ATM依存反応は,末端フォークの完全性にとって不可欠であり,ゲノム不安定症候群とテロメア生物学に影響があります.
関連する概念動画
Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Residual Stresses in Circular Shafts
In materials that exhibit elastic and plastic behavior, known as elastoplastic materials, residual stresses can accumulate when these materials experience plastic deformation. This deformation arises from either high levels of shearing stress or significant strains. Residual stresses are internal stresses that persist within a material after removing the external force causing deformation. This phenomenon is demonstrated when observing the behavior of a shaft under torque; notably, the shaft's...
Stability of structures
In mechanical engineering, the stability of systems under various forces is critical for designing durable and efficient structures. One fundamental way to explore these concepts is by analyzing systems like two rods connected at a pivot point, O, with a torsional spring of spring constant k at the pivot point. This system is similar in appearance to a scissor jack used to change tires on a car. In this case, the arms of the linkage (equivalent to the rods in this system) are entirely vertical,...
Chain Reactions
Chain reactions involve highly reactive transient species, such as atoms or free radicals, as intermediates. These intermediates facilitate rapid reactions over an extended period. The process includes a series of steps: a reactive intermediate is consumed, reactants are converted to products, and the intermediate is regenerated. This cycle enables continuous repetition, amplifying the production of products with a small amount of intermediate. Chain reactions often utilize free radicals as...

