GO:0110026 regulation of DNA strand resection involved in replication fork processing: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0110026 describes any process that modulates the frequency, rate or extent of DNA strand resection specifically during replication fork processing, a critical step in replication fork repair and restart.
• DNA strand resection at stalled or damaged replication forks is a prerequisite for homologous recombination-mediated fork restart and for the recruitment of factors that protect or process the fork.
• The DNA2 nuclease/helicase is a central regulator of resection, with multiple roles in DNA metabolism, genome stability, and human disease.
• RecBCD and RecD2 helicase/nuclease complexes regulate resection and are required for completion of chromosomal replication in bacteria, illustrating evolutionary conservation of fork-processing mechanisms.
• Chromatin modification and the MRN complex component NBS1 influence resection and double-strand break repair, linking regulation of resection to genome maintenance pathways.
• Dysregulation of replication fork resection is associated with cancer, genome instability, and diseases such as those caused by DNA2 mutations.
Description
GO:0110026, regulation of DNA strand resection involved in replication fork processing, is a biological process term that captures the control of nucleolytic degradation of nascent DNA strands at replication forks. When replication forks encounter DNA damage or obstacles, they stall and require processing to restart; regulated resection generates single-stranded DNA that is essential for homologous recombination and fork protection. This process is tightly controlled to prevent excessive degradation and genome instability. Understanding this regulation is fundamental for researchers studying DNA repair, replication stress, and cancer biology, as well as for developing therapeutic strategies targeting replication-associated vulnerabilities.
regulation of DNA strand resection involved in replication fork processing At A Glance
| GO ID | GO:0110026 |
|---|---|
| GO term | regulation of DNA strand resection involved in replication fork processing |
| Ontology | biological_process |
| Synonym | none |
| Major function | Modulates the frequency, rate or extent of DNA strand resection during replication fork processing |
| Related processes | DNA replication, DNA repair, homologous recombination, replication fork restart |
| Key regulators | DNA2, RecBCD, RecD2, NBS1, chromatin modifiers |
| Disease relevance | Cancer, genome instability, DNA2-related disorders |
What Is GO:0110026?
According to the Gene Ontology, GO:0110026 is defined as any process that modulates the frequency, rate or extent of DNA strand resection involved in replication fork processing. In other words, it encompasses the molecular mechanisms that control how much, how fast, and under what conditions the ends of nascent DNA strands are resected at replication forks that have stalled or encountered damage.
Why Is regulation of DNA strand resection involved in replication fork processing Important in Cell Biology?
Regulation of DNA strand resection at replication forks is critical for maintaining genome stability and preventing cancer. Excessive or insufficient resection can lead to fork collapse, chromosomal rearrangements, and cell death. The process is also a determinant of chemotherapy and radiotherapy responses, as many anticancer agents target replication and repair pathways. Therefore, understanding GO:0110026 provides insights into fundamental DNA metabolism and offers potential targets for therapeutic intervention.
• Controls the extent of single-stranded DNA generation at stalled forks, which is essential for homologous recombination-mediated fork restart.
• Prevents excessive nucleolytic degradation that could lead to fork collapse and genome instability.
• Regulates the recruitment of DNA repair proteins and checkpoint factors to damaged forks.
• Influences sensitivity to DNA-damaging agents used in cancer therapy.
• Is conserved from bacteria to humans, with RecBCD and RecD2 as bacterial paradigms.
• Dysregulation is linked to cancer predisposition and neurodegenerative disorders.
• Plays a role in the completion of chromosomal replication under stress conditions.
• Interacts with chromatin remodeling and histone modifications that affect resection efficiency.
• Provides a mechanism for fork protection versus fork restart decisions.
• Is a potential target for synthetic lethal strategies in cancer cells with replication stress.
What Happens During regulation of DNA strand resection involved in replication fork processing?
Initiation of resection at stalled forks
In simple terms: When a replication fork stalls, the first step is to decide whether and where to cut the DNA ends to create single-stranded DNA.
Upon fork stalling, the MRN complex (MRE11-RAD50-NBS1) and other nucleases are recruited to initiate short-range resection. NBS1, a component of the MRN complex, is involved in DNA double-strand break repair and chromatin modification, influencing the initiation of resection. In bacteria, RecBCD is required to process DNA ends and complete chromosomal replication, highlighting the conserved need for regulated resection.
Long-range resection and DNA2
In simple terms: After the initial cut, longer stretches of DNA are resected to expose single-stranded DNA for repair proteins.
DNA2 nuclease/helicase plays multiple roles in DNA metabolism, including long-range resection at replication forks. It collaborates with helicases to degrade the 5' strand, generating 3' single-stranded DNA overhangs. This step is critical for homologous recombination and fork restart. In Bacillus subtilis, RecD2, a helicase/nuclease, interacts with RecG or RuvAB to process recombination intermediates, demonstrating the importance of coordinated resection.
Protection and regulation of resected forks
In simple terms: The resected DNA must be protected from further degradation and from inappropriate repair to avoid genome instability.
The extent of resection is tightly regulated by fork protection factors such as BRCA1/2 and the checkpoint machinery. Chromatin modifications, including those mediated by NBS1, influence the accessibility of resection enzymes to DNA. DNA2 activity is also regulated by post-translational modifications and protein-protein interactions to prevent excessive resection. In bacteria, RecD2 and RecG/RuvAB coordinate to balance resection and recombination.
Resolution and fork restart
In simple terms: Once the fork is processed, it can restart replication or be repaired, completing the replication fork processing pathway.
After resection, the single-stranded DNA invades a homologous template, leading to fork restart via homologous recombination. RecBCD is required for the completion of chromosomal replication, suggesting that resection is coupled to replication termination and repair. DNA2 also participates in the resolution of recombination intermediates, ensuring proper fork restart and genome stability. Failure of these steps can result in fork collapse and cell death.
Key Genes Involved in GO:0110026 regulation of DNA strand resection involved in replication fork processing
The following genes and proteins are key players in the regulation of DNA strand resection during replication fork processing, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DNA2 | Nuclease/helicase that performs long-range resection and processes replication forks | Central regulator of resection; mutations linked to human diseases |
| NBS1 | Component of MRN complex; involved in DNA double-strand break repair and chromatin modification | Regulates initiation of resection and fork repair |
| RecBCD | Bacterial helicase/nuclease complex that processes DNA ends | Required for completion of chromosomal replication and double-strand break repair |
| RecD2 | Bacterial helicase/nuclease that interacts with RecG or RuvAB | Plays a role in recombinational repair and fork processing |
| RecG | Bacterial helicase involved in recombination and fork reversal | Interacts with RecD2 in recombinational repair |
| RuvAB | Bacterial helicase complex that processes Holliday junctions | Interacts with RecD2 in recombinational repair |
| MRE11 | Nuclease component of MRN complex | Initiates resection at DNA breaks |
| RAD50 | Component of MRN complex | Structural and regulatory roles in resection |
| BRCA1 | Fork protection and homologous recombination factor | Regulates resection extent and fork stability |
| BRCA2 | Homologous recombination mediator | Protects resected forks and promotes RAD51 loading |
| RAD51 | Recombinase that binds single-stranded DNA | Essential for fork restart after resection |
| EXO1 | Exonuclease involved in long-range resection | Processes DNA ends during resection |
| BLM | Helicase that resolves recombination intermediates | Cooperates with DNA2 in resection |
| WRN | Helicase/exonuclease involved in replication and repair | Interacts with DNA2 in fork processing |
| ATR | Checkpoint kinase that responds to replication stress | Regulates resection and fork stability |
| CHK1 | Checkpoint kinase downstream of ATR | Controls cell cycle and resection |
| FANCD2 | Fanconi anemia protein involved in replication fork repair | Links resection to crosslink repair |
How Is regulation of DNA strand resection involved in replication fork processing Regulated?
The regulation of DNA strand resection at replication forks is controlled by multiple mechanisms, including post-translational modifications of resection enzymes, chromatin remodeling, and checkpoint signaling. DNA2 activity is modulated by phosphorylation and interactions with BLM and WRN helicases. The MRN complex, particularly NBS1, is regulated by chromatin modifications that affect its recruitment to damage sites. In bacteria, RecBCD and RecD2 activities are coordinated with RecG and RuvAB to balance resection and recombination. Checkpoint kinases such as ATR and CHK1 also influence resection by controlling cell cycle progression and repair factor recruitment.
regulation of DNA strand resection involved in replication fork processing and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DNA2 | Seckel syndrome-like, progressive external ophthalmoplegia, cancer | Knockout or point-mutation cell lines; patient-derived fibroblasts |
| NBS1 | Nijmegen breakage syndrome, cancer predisposition | Knockout and knock-in models; chromatin modification studies |
| BRCA1/2 | Hereditary breast and ovarian cancer | Knockout cell lines; resection assays |
| RecBCD | Bacterial genome stability and replication completion | Bacterial knockout strains; biochemical assays |
| RecD2 | Bacterial recombinational repair defects | Bacterial knockout and point-mutation strains |
Cancer and genome instability
Dysregulation of DNA strand resection at replication forks leads to genome instability, a hallmark of cancer. DNA2 mutations or altered expression are associated with cancer predisposition and progression. Defects in resection regulation can cause hypersensitivity to DNA-damaging agents and synthetic lethality with other repair pathways, offering therapeutic opportunities.
DNA2-related disorders
Mutations in DNA2 cause a spectrum of human diseases characterized by genome instability, including Seckel syndrome-like phenotypes and progressive external ophthalmoplegia. These disorders underscore the importance of precise resection regulation for human health.
Neurodegeneration
Impaired replication fork processing and resection can contribute to neurodegeneration, as post-mitotic neurons are particularly sensitive to DNA damage. DNA2 dysfunction has been linked to neurodegenerative phenotypes in model systems.
From regulation of DNA strand resection involved in replication fork processing-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does DNA2 knockout affect replication fork resection? | DNA2 knockout cell lines (e.g., HCT116, U2OS) |
| What is the effect of a specific DNA2 point mutation on resection? | Point-mutation knock-in cell lines |
| How does NBS1 phosphorylation regulate resection? | NBS1 knock-in with phospho-mutant |
| Can overexpression of DNA2 rescue resection defects? | DNA2 overexpression cell lines |
| What is the role of RecBCD in chromosomal replication? | Bacterial RecBCD knockout strains |
| How does RecD2 interact with RecG/RuvAB? | Bacterial two-hybrid and knockout models |
How to Study the regulation of DNA strand resection involved in replication fork processing Process
| Method | What It Measures | Typical Application |
|---|---|---|
| DNA fiber assay | Replication tract length and fork progression | Assessing resection and restart after damage |
| ChIP-qPCR | Recruitment of resection factors to forks | Studying NBS1 and DNA2 localization |
| In vitro nuclease assay | DNA degradation activity | Measuring DNA2 or RecBCD activity |
| CRISPR screen | Genes affecting resection and fork stability | Identifying novel regulators |
| Electron microscopy | DNA structures at forks | Visualizing resected intermediates |
| Mass spectrometry | Protein interactions | Mapping resection complex components |
| Live-cell imaging | Fork dynamics and resection | Real-time analysis of fork processing |
| Comet assay | DNA breaks and resection | Quantifying DNA damage |
DNA fiber assays
DNA fiber assays measure replication tract lengths and fork progression, allowing assessment of resection and fork restart after damage. They are widely used to study regulators such as DNA2 and BRCA1/2.
Chromatin immunoprecipitation (ChIP)
ChIP can determine the recruitment of resection factors like NBS1 and DNA2 to stalled forks, providing spatial and temporal information.
Biochemical resection assays
In vitro assays using purified proteins (e.g., DNA2, RecBCD) and DNA substrates measure nuclease and helicase activities, revealing mechanistic details of resection.
Genome-wide sequencing
Whole-genome sequencing and CRISPR screens can identify genes that regulate resection and fork processing, linking genotype to phenotype.
How CRISPR Can Be Used to Study GO:0110026 regulation of DNA strand resection involved in replication fork processing
Knockout
CRISPR knockout of DNA2 or NBS1 can abolish resection, leading to fork instability and sensitivity to replication stress. These models are used to study the essential roles of these genes in fork processing.
Point Mutation
Point mutations in the nuclease or helicase domains of DNA2 can separate its resection functions from other roles. Knock-in of such mutations allows precise structure-function analysis.
Knock-in
Knock-in of tagged versions of resection proteins (e.g., GFP-DNA2) enables live-cell imaging and proteomic studies. Knock-in of phospho-mutants helps dissect regulation by post-translational modifications.
Overexpression
Overexpression of DNA2 or RecBCD can enhance resection and may rescue defects in other repair pathways. These models are useful for testing sufficiency of resection factors.
How EDITGENE Supports regulation of DNA strand resection involved in replication fork processing Research
Researchers studying regulation of DNA strand resection involved in replication fork processing-related genes often need to determine whether a candidate gene is causally involved in fork stability, resection, or repair. EDITGENE provides a comprehensive suite of CRISPR services to generate precisely engineered cell models for such investigations.
Contact EDITGENE today to design your custom CRISPR model for regulation of DNA strand resection involved in replication fork processing research.
Frequently Asked Questions About regulation of DNA strand resection involved in replication fork processing
What is GO:0110026?
GO:0110026 is a Gene Ontology biological process term defined as any process that modulates the frequency, rate or extent of DNA strand resection involved in replication fork processing.
What genes are involved in regulation of DNA strand resection involved in replication fork processing?
Key genes include DNA2, NBS1, RecBCD, RecD2, BRCA1, BRCA2, and RAD51, among others.
Why is regulation of DNA strand resection important?
It ensures proper fork restart and prevents genome instability, which is critical for cancer prevention and therapy.
How is DNA strand resection regulated at replication forks?
It is regulated by nucleases like DNA2, helicases, checkpoint kinases, and chromatin modifications.
What diseases are associated with defects in this process?
Cancer, DNA2-related disorders, and neurodegeneration have been linked to dysregulation of resection.
What methods are used to study regulation of DNA strand resection?
DNA fiber assays, ChIP, in vitro nuclease assays, and CRISPR screens are commonly used.
Can CRISPR be used to study this process?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are powerful tools for dissecting resection regulation.
What is the role of DNA2 in resection?
DNA2 is a nuclease/helicase that performs long-range resection and processes replication forks, with multiple roles in genome stability.
How does NBS1 regulate resection?
NBS1, as part of the MRN complex, is involved in the initiation of resection and chromatin modification at damage sites.
What is the bacterial equivalent of resection regulation?
In bacteria, RecBCD and RecD2 regulate resection and are required for chromosomal replication and recombinational repair.
Conclusion
GO:0110026, regulation of DNA strand resection involved in replication fork processing, is a fundamental biological process that safeguards genome stability by controlling the nucleolytic processing of stalled replication forks. Key regulators such as DNA2, NBS1, and bacterial RecBCD/RecD2 have been characterized, and their dysfunction is linked to cancer and other diseases. Continued research using advanced CRISPR models and biochemical assays will further illuminate the mechanisms and therapeutic potential of this pathway.
References
- 1. Zheng L et al.. 2020. Multiple roles of DNA2 nuclease/helicase in DNA metabolism, genome stability and human diseases.. Nucleic Acids Res 48(1):16-35 PMID: 31754720
- 2. Saito Y et al.. 2016. Chromatin modification and NBS1: their relationship in DNA double-strand break repair.. Genes Genet Syst 90(4):195-208 PMID: 26616756
- 3. Patel DR et al.. 2018. A tough row to hoe: when replication forks encounter DNA damage.. Biochem Soc Trans 46(6):1643-1651 PMID: 30514768
- 4. Courcelle J et al.. 2015. RecBCD is required to complete chromosomal replication: Implications for double-strand break frequencies and repair mechanisms.. DNA Repair (Amst) 32:86-95 PMID: 26003632
- 5. Torres R et al.. 2017. Interplay between Bacillus subtilis RecD2 and the RecG or RuvAB helicase in recombinational repair.. DNA Repair (Amst) 55:40-46 PMID: 28527403
