相关实验视频
Updated: Jul 14, 2025

07:55
Visualization of DNA Repair Proteins Interaction by Immunofluorescence
Published on: June 26, 2020
10.3K
用MRE11和EXO1核酶对复制应激衍生的新生链DNA缺口进行多步处理
Anastasia Hale1, Ashna Dhoonmoon1, Joshua Straka1
1Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
Nature communications
|October 7, 2023
概括
在复制过程中形成的单链DNA (ssDNA) 缺口通过核分解处理转化为DNA双链断裂 (DSB). 这种机制受到BPA和DEHP等环境污染物的影响,导致基因组不稳定.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 环境健康 环境健康
背景情况:
- 在复制过程中新生链中的单链DNA (ssDNA) 缺口与细胞毒性和基因毒性应激敏感性有关,特别是当BRCA瘤抑制路径受到损害时.
- 通过ssDNA缺口导致基因毒性的确切机制仍然不完全理解.
研究的目的:
- 为了阐明复制应激诱导ssDNA差距的核分解性处理.
- 研究BRCA通路在抑制ssDNA间隙处理中的作用.
- 确定像双甲 (BPA) 和二甲基甲酸盐 (DEHP) 这样的环境污染物是否会诱导ssDNA缺口和随后的DNA损伤.
主要方法:
- 使用分子生物学技术,对ssDNA缺口的核分解性处理进行表征.
- 研究MRE11和EXO1在ssDNA间隙扩展和处理中的参与.
- 评估BRCA通路状态对ssDNA缺口处理的影响.
- 细胞暴露于BPA和DEHP以评估它们对ssDNA间隙形成和处理的影响.
主要成果:
- 复制压力诱导的ssDNA缺口通过多步核分解途径被加工成细胞毒性双链DNA断裂 (DSB).
- MRE11和EXO1酶双向扩展ssDNA间隙,这是BRCA通路抑制的过程.
- MRE11内核酶活性在ssDNA间隙中切割父链,产生DSBs.
- 暴露于BPA和DEHP会诱导新生链的ssDNA间隙,这些间隙通过相同的机制被加工成DSB.
结论:
- ssDNA缺口是基因组不稳定性和细胞毒性的重要驱动因素.
- 一个保存的核分解机制将ssDNA缺口处理成DSB,突出显示了DNA复制和修复途径的重要性.
- 环境污染物BPA和DEHP可以通过诱导ssDNA缺口和随后的DSB形成来促进基因组不稳定.
相关概念视频
Homologous Recombination
50.6K
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...
50.6K
Mismatch Repair
4.9K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
4.9K
Restarting Stalled Replication Forks
5.8K
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,...
5.8K
Nucleotide Excision Repair
37.2K
Overview
37.2K
The DNA Replication Fork
36.1K
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...
36.1K
Base Excision Repair
22.4K
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...
22.4K

