在复制应激过程中,PRIMPOL产生的新生的DNA链不连续性的USP1依赖的核分解扩张
Alexandra Nusawardhana1, Lindsey M Pale1, Claudia M Nicolae1
1Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
Nucleic acids research
|January 5, 2024
概括
复制压力会造成DNA缺口,这些缺口会被MRE11和EXO1核酶扩大. 脱泛化酶USP1促进了这种扩张,导致DNA断裂和基因组不稳定.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 基因组学就是基因组学.
背景情况:
- 复制压力会导致DNA分叉停止,威胁到基因组完整性.
- 以PRIMPOL为媒介的镇压会产生单链DNA (ssDNA) 缺口,这与BRCA缺乏细胞的过敏性有关.
- 对ssDNA缺口转化为细胞毒性结构的理解仍然很差.
研究的目的:
- 为了研究在复制压力期间处理PRIMPOL依赖的ssDNA缺口.
- 确定参与ssDNA间隙扩张和其调节的关键酶.
- 阐明USP1在ssDNA间隙动态和基因组不稳定中的作用.
主要方法:
- 基urea 和 cisplatin 治疗以诱导复制应激.
- 在PRIMPOL过度表达细胞中分析ssDNA缺口处理.
- 研究MRE11,EXO1,USP1和PCNA无处不在的作用.
主要成果:
- PRIMPOL依赖的ssDNA间隙由MRE11 (3'-5') 和EXO1 (5'-3') 核酶双向扩大.
- USP1促进了MRE11和EXO1.1的ssDNA间隙积累和扩张.
- USP1的活性与PCNA脱泛化有关,这表明泛化PCNA限制差距的积累.
- USP1的耗尽减少了PRIMPOL过度表达细胞中的双链断裂 (DSB) 的形成.
结论:
- 双向核溶解扩张ssDNA间隙有助于DSB的形成.
- 通过促进ssDNA间隙扩张,USP1意外地促进了基因组的不稳定.
- USP1在PCNAde-ubiquitination中的作用对于在复制压力期间调节ssDNA间隙动态至关重要.
相关概念视频
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
Translesion DNA Polymerases
10.0K
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
10.0K
The DNA Replication Fork
36.0K
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...
36.0K
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
The Replisome
33.5K
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
33.5K
DNA Topoisomerases
31.3K
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
31.3K


