相关实验视频
Updated: May 7, 2026

07:55
Visualization of DNA Repair Proteins Interaction by Immunofluorescence
Published on: June 26, 2020
Sae2,Exo1和Sgs1在DNA双链断裂处理中进行合作
Eleni P Mimitou1, Lorraine S Symington
1Department of Microbiology, Columbia University Medical Center, 701 West 168th Street, New York, New York 10032, USA.
Nature
|September 23, 2008
概括
酵母 Exo1 核酶和 Sgs1 螺旋酶通过替代途径处理 DNA 双链断裂 (DSB). Sae2对于早期的DSB处理至关重要,Exo1和Sgs1在随后的步骤中起作用,产生同源重组的基质.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 修复DNA修复DNA的修复
背景情况:
- DNA双链断裂 (DSBs) 触发同源重组 (HR) 进行修复.
- 处理DSBs涉及5'-3'核溶解降解,以创建单链DNA (ssDNA) 基底为Rad51.1.
- 在DSB处理中涉及的关键因素包括Mre11复合体,Sae2和Exo1.
研究的目的:
- 阐明酵母EXO1核酶和Sgs1酶在DSB处理中的作用.
- 研究SAE2,EXO1和Sgs1在产生同类重组基质中的相互作用.
- 定义涉及到真核体DSB末端切除的机械步骤.
主要方法:
- 对缺乏DSB处理因子 (Exo1,Sgs1,Sae2) 的酵母突变菌的遗传分析.
- 在特定突变背景中积累的DNA修复中间体的表征.
- 评估突变对同源重组效率的影响.
主要成果:
- 酵母 Exo1 和 Sgs1 在 DSB 处理过程中并行运行.
- 部分切除的DSB中间体在exo1 sgs1双突变体中的积累.
- Sae2对于产生这些中间体的初始加工步骤至关重要.
- 缺少Sae2导致未经处理的DSB积累,并导致同质性依赖修复的失败.
结论:
- 在同源重组过程中,DSB处理遵循两步机制.
- 步骤1:Mre11复合物和Sae2通过去除寡核酸来产生早期中间体.
- 步骤2:Exo1和/或Sgs1广泛切除这种中间体,产生ssDNA用于Rad51结合和HR启动.
相关概念视频
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
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...
Base Excision Repair
One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
The first step of...
Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
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...

