Related Experiment Video
Updated: Jul 3, 2026
08:53
Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method
Published on: May 2, 2025
Multiple pathways cooperate to facilitate DNA replication fork progression through alkylated DNA.
María Victoria Vázquez1, Vanesa Rojas, José Antonio Tercero
1Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, Madrid, Spain.
DNA Repair
|July 22, 2008
Summary
DNA replication forks require DNA repair pathways, including base excision repair, and the S-phase checkpoint to maintain genome stability and cell survival when encountering DNA damage during S phase.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Eukaryotic genome stability is threatened by DNA damage during S phase, when DNA replication occurs.
- Replication fork integrity is crucial for accurate chromosome duplication and is compromised by DNA lesions.
- The S-phase checkpoint and DNA repair pathways are vital for protecting replication forks and maintaining genome integrity.
Purpose of the Study:
- To investigate the roles of DNA repair pathways and the S-phase checkpoint in enabling replication fork progression through damaged DNA.
- To elucidate how different DNA repair mechanisms contribute to tolerance and repair of DNA lesions during replication.
Main Methods:
- Utilized budding yeast as a model organism.
- Induced DNA damage using the alkylating agent methyl methanesulfonate (MMS).
- Assessed the impact of DNA repair pathway deficiencies (base excision repair, homologous recombination, DNA damage tolerance) and S-phase checkpoint function on replication fork progression and cell survival.
Main Results:
- Base excision repair, homologous recombination, DNA damage tolerance pathways, and a functional S-phase checkpoint are essential for efficient replication fork progression and cell survival following MMS treatment.
- In the absence of base excision repair, replication forks stall reversibly when exposed to MMS.
- Effective lesion repair by base excision repair must be coordinated with recombination and damage tolerance to prevent fork collapse and allow replication to resume.
Conclusions:
- Base excision repair is critical for removing DNA lesions that impede replication fork progression.
- Coordination between base excision repair, homologous recombination, and DNA damage tolerance pathways is necessary for maintaining replication fork stability and genome integrity.
- The S-phase checkpoint plays a crucial role in supporting replication fork progression through damaged DNA, ensuring cell survival.
Related Concept Videos
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...
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...
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...
02:36DNA 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...