相关实验视频
Updated: Jun 13, 2026
07:27
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Published on: April 29, 2010
转录因子DksA可以防止DNA复制和转录机制之间的冲突
Ashley K Tehranchi1, Matthew D Blankschien, Yan Zhang
1Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
Cell
|May 19, 2010
概括
营养反应性转录因子DksA通过消除转录障碍,防止饥饿期间的DNA复制中断. 这确保了复制分叉的进展和DNA完整性,独立于其启动活动.
科学领域:
- 分子生物学分子生物学
- 微生物学 微生物学
- 遗传学 是一个遗传学.
背景情况:
- 细胞DNA复制必须保持准确,尽管营养的可用性波动.
- 在营养压力下防止复制中断的因素尚未完全理解.
研究的目的:
- 研究DksA在营养稀缺期间维持DNA复制忠实性的作用.
- 阐明DksA阻止复制停止的机制.
主要方法:
- 使用了缺乏DksA的埃舍里希亚大肠杆菌突变.
- 在氨基酸饥饿条件下研究复制停止.
- 分析了转录和RNA聚合酶活动对复制的影响.
主要成果:
- 在氨基酸饥饿期间,DksA缺失会导致快速复制停止,需要活性转录.
- 复制停止被RNA聚合酶突变减轻,并且独立于外源DNA损伤.
- DksA的作用涉及其转录延长活动,而不是启动,并由GreA/B因素支持.
结论:
- 包括DksA在内的转录延长因子对于解决复制和转录之间的冲突至关重要.
- 这些因素保护复制叉的进展,并在营养压力下保持DNA完整性.
相关概念视频
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.
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.
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...
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...
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...
02:36DNA 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...