在完整的DNA复制之前的亚纳相发作与完整的检查点反应.
Jordi Torres-Rosell1, Giacomo De Piccoli, Violeta Cordon-Preciado
1Cell Cycle Group, Medical Research Council (MRC) Clinical Sciences Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
Science (New York, N.Y.)
|March 10, 2007
概括
细胞检查点防止了与停滞的DNA复制分叉的线粒分裂. 然而,这项研究表明,Smc5-Smc6复合体对于在细胞分裂之前完成复制至关重要,独立于已知的检查点.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 细胞检查点通常会停止细胞分裂,如果DNA复制分叉停滞.
- 目前尚不清楚检查点是否能确保在线转化之前的DNA复制完成.
研究的目的:
- 为了调查DNA复制完成是否通过细胞检查点在线粒分裂前监测.
- 了解Smc5-Smc6复合体在复制和细胞分裂中的作用.
主要方法:
- 利用酵母smc5-smc6突变来研究DNA复制和分裂.
- 分析了自然复制阻碍位点的复制时间,包括核糖体DNA基因集群.
- 在没有功能性Smc5-Smc6.6的情况下研究了染色体分离.
主要成果:
- 在smc5-smc6突变体中,复制显著延迟,特别是在核糖体DNA位置.
- 在smc5-smc6突变体中发生了 mitotic 进入与未完成的复制,导致染色体不分裂.
- 在smc5-smc6突变体中移除复制叉障碍物恢复了复制和分离之间的时间合.
结论:
- Smc5-Smc6复合体对于在线分裂之前及时完成DNA复制至关重要.
- 已知的细胞检查点似乎没有监视DNA复制的完成.
- 在缺乏功能性的smc5-smc6突变体中,复制完成和染色体分离是暂时脱离的smc5-smc6.
相关概念视频
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In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
02:36DNA Damage Can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
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02:37Restarting 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...
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In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
02:38S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.