相关实验视频
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07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 30, 2010
在S阶段内检查点的目标是Dna2,以防止停滞不前的复制分叉逆转
Jiazhi Hu1, Lei Sun, Fenfen Shen
1The National Laboratory of Protein Engineering and Plant Genetic Engineering, The College of Life Sciences, Peking University, Beijing, China.
Cell
|June 12, 2012
概括
Cds1激酶准Dna2,以防止在复制压力期间反复复制叉的反转. 这种机制稳定了停滞的分叉,保持了基因组的稳定性,并防止了细胞死亡.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 遗传学 是一个遗传学.
背景情况:
- 复制叉在压力下停滞不前,需要检查点进行稳定和重新启动.
- 在S相内检查点的缺陷导致分叉崩和细胞死亡.
研究的目的:
- 调查Cds1效应酶和Dna2在稳定停滞不前的复制分叉中的作用.
- 阐明Dna2阻止复制叉反转的机制.
主要方法:
- 利用裂变酵母作为一个模型生物.
- 研究了Dna2与停滞的复制分叉的体内和体外关联.
- 评估了Dna2酸化和核酶活性在防止分叉逆转方面的要求.
- 在模型复制叉上通过Dna2分析回归的新生链的裂变.
主要成果:
- Cds1 (Chk2) 针对S220上的Dna2,以调节其与停滞不前的复制分叉的关联.
- 在S220的Dna2酸化及其核酶活性对于防止复制叉反转至关重要.
- Dna2有效地分裂回归的领先或滞后链,是分叉回归的前体.
- Dna2的裂变活性阻止了叉子的反转,从而稳定了停滞的叉子.
结论:
- 回归的新生链的Dna2分裂是防止复制叉反转的关键机制.
- 这一过程稳定了停滞的分叉,在复制压力期间促进了基因组的稳定性.
- 在基因毒性压力下,Cds1-Dna2通路对于保持复制忠实性至关重要.
相关概念视频
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01:02The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
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...
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...