GO:2000819 regulation of nucleotide-excision repair: Regulatory Mechanisms, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:2000819 (regulation of nucleotide-excision repair) encompasses any process that modulates the frequency, rate or extent of nucleotide-excision repair (NER).
• NER is the primary DNA repair pathway that removes bulky helix-distorting lesions such as UV-induced pyrimidine dimers and intrastrand crosslinks.
• Regulation occurs at multiple levels: damage recognition, chromatin accessibility, transcription coupling, and post-translational modification of core NER factors.
• Key regulatory nodes include the CRL4-DDB2 ubiquitin ligase, the TFIIH complex, XPA, XPC, and the endonucleases XPF-ERCC1 and XPG.
• Dysregulation of NER regulation is linked to cancer predisposition, chemotherapy resistance, and accelerated ageing.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models are essential to dissect causal roles of NER regulatory genes.
Description
Nucleotide-excision repair (NER) is a highly conserved DNA repair pathway that removes a wide spectrum of bulky, helix-distorting DNA lesions, including ultraviolet (UV)-induced cyclobutane pyrimidine dimers and 6-4 photoproducts, as well as intrastrand and interstrand crosslinks. The Gene Ontology term GO:2000819, regulation of nucleotide-excision repair, describes any process that modulates the frequency, rate or extent of this repair pathway. Because unrepaired NER substrates block transcription and replication and drive mutagenesis, the regulation of NER is critical for genome stability, organismal survival, and cancer avoidance. Researchers study GO:2000819 to understand how cells prioritize damage recognition, assemble repair complexes at the right time and place, and coordinate NER with other DNA transactions such as transcription and chromatin remodeling. The regulatory layer of NER is now recognized as a major determinant of therapeutic response, since many cancers alter NER capacity to survive genotoxic chemotherapy. This article provides a research-grade synthesis of the mechanisms, key genes, disease links, and experimental models relevant to GO:2000819, based exclusively on published literature.
regulation of nucleotide-excision repair At A Glance
| GO ID | GO:2000819 |
|---|---|
| GO term | regulation of nucleotide-excision repair |
| Ontology | biological_process |
| Synonym | regulation of NER; regulation of pyrimidine-dimer repair; regulation of interstrand crosslink repair; regulation of intrastrand cross-link repair; DNA damage excision |
| Major function | Modulates the frequency, rate or extent of nucleotide-excision repair, thereby influencing genome stability and cell survival after DNA damage. |
| Key regulatory nodes | CRL4-DDB2, TFIIH, XPA, XPC, XPF-ERCC1, XPG, and chromatin remodelers. |
| Associated diseases | Xeroderma pigmentosum, Cockayne syndrome, cancer predisposition, and chemotherapy resistance. |
| Research methods | CRISPR knockout/knock-in, RNA-seq, ChIP-seq, proteomics, and comet/UNEL assays. |
What Is GO:2000819?
GO:2000819 (regulation of nucleotide-excision repair) is defined as any biological process that modulates the frequency, rate or extent of nucleotide-excision repair. In practice, this includes mechanisms that control damage recognition, the assembly and activity of NER incision complexes, chromatin accessibility at lesion sites, and the coupling of NER to transcription. The term is a biological_process and has synonyms such as regulation of NER, regulation of pyrimidine-dimer repair, regulation of interstrand crosslink repair, regulation of intrastrand cross-link repair, and DNA damage excision.
Why Is regulation of nucleotide-excision repair Important in Cell Biology?
Understanding GO:2000819 is essential because the regulation of NER determines whether cells survive genotoxic stress or accumulate mutations that drive cancer and ageing. NER is the sole pathway that removes UV-induced pyrimidine dimers and many bulky adducts, and its dysregulation is directly linked to xeroderma pigmentosum, Cockayne syndrome, and a broad spectrum of cancers. Moreover, NER activity influences the efficacy of platinum-based chemotherapies and other DNA-damaging agents, making its regulatory mechanisms attractive targets for therapeutic intervention. Studying GO:2000819 also illuminates fundamental principles of how cells coordinate DNA repair with transcription, chromatin remodeling, and cell-cycle progression.
• NER regulation determines cellular sensitivity to UV radiation and environmental carcinogens.
• Dysregulated NER is a hallmark of xeroderma pigmentosum and Cockayne syndrome.
• NER capacity modulates response to platinum-based chemotherapy and radiotherapy.
• Regulation of NER is critical for transcription-coupled repair and recovery of RNA synthesis after damage.
• Chromatin remodeling and histone modifications regulate access of NER factors to lesions.
• Post-translational modifications of XPA, XPC, and DDB2 control NER efficiency.
• NER regulation intersects with cell-cycle checkpoints and apoptosis.
• Understanding NER regulation can guide development of targeted cancer therapies.
• NER regulatory factors are potential biomarkers for cancer risk and treatment response.
• CRISPR screens have identified novel regulators of NER and DNA damage response.
What Happens During regulation of nucleotide-excision repair?
Damage recognition and initial regulation
In simple terms: The cell first finds the DNA damage and decides whether to repair it.
In global-genome NER (GG-NER), the XPC-RAD23B complex and the UV-DDB (DDB1-DDB2) complex recognize helix-distorting lesions. Regulation at this step involves ubiquitination of DDB2 by the CRL4-DDB2 ligase, which enhances damage recognition and recruits XPC. In transcription-coupled NER (TC-NER), RNA polymerase II stalling at a lesion recruits CSB, CSA, and other factors to initiate repair. The choice between GG-NER and TC-NER is a key regulatory decision that depends on lesion location and transcription activity.
Chromatin remodeling and access
In simple terms: The DNA is wrapped around proteins, so the cell must open up the packaging to reach the damage.
Chromatin structure is a major barrier to NER, and its regulation is essential for repair. Histone modifications such as acetylation, methylation, and ubiquitination, as well as ATP-dependent chromatin remodelers, facilitate access of NER factors to lesions. For example, UV-DDB recruits the chromatin remodeler ALC1 to promote nucleosome sliding and repair. Epigenetic regulation of NER is increasingly recognized as a determinant of repair efficiency and cellular sensitivity to DNA-damaging agents.
Pre-incision complex assembly and regulation
In simple terms: A team of proteins assembles on the damage to prepare for cutting the DNA.
After damage recognition, TFIIH is recruited and its helicase subunits XPB and XPD unwind DNA around the lesion. XPA binds to the damaged strand and helps position the incision complex, while RPA stabilizes the undamaged strand. The assembly of this pre-incision complex is regulated by protein-protein interactions, post-translational modifications, and the availability of core factors. Regulatory phosphorylation of XPA and other factors can modulate complex stability and repair efficiency.
Dual incision and excision
In simple terms: The damaged piece of DNA is cut out.
The endonucleases XPF-ERCC1 and XPG make incisions 5' and 3' to the lesion, respectively, excising a 24-32 nucleotide fragment. Regulation of endonuclease activity is critical to avoid aberrant incisions and genomic instability. The order and coordination of dual incision are tightly controlled, and defects in this step cause severe repair deficiencies. After excision, the gap is filled by DNA polymerase and sealed by ligase.
Repair synthesis and ligation
In simple terms: The missing DNA is rebuilt and sealed.
DNA polymerase delta or epsilon, with the help of PCNA and RFC, fills the excised gap using the undamaged strand as a template. The final nick is sealed by DNA ligase I or III. Regulation of repair synthesis ensures accurate restoration of the DNA sequence and is coupled to cell-cycle progression. Failure of this step can lead to persistent single-strand breaks and replication stress.
Key Genes Involved in GO:2000819 regulation of nucleotide-excision repair
The following genes and proteins are central to the regulation of nucleotide-excision repair (GO:2000819) and are frequently studied using CRISPR-based models.
| Gene | Major Role | Research Relevance |
|---|---|---|
| XPC | Damage recognition in GG-NER | Mutations cause xeroderma pigmentosum; target for knockout studies |
| DDB2 | UV-damaged DNA binding; recruits XPC | Regulated by CRL4 ubiquitination; knockout sensitizes to UV |
| XPA | Damage verification and pre-incision complex assembly | Phosphorylation regulates NER; knockout impairs repair |
| XPB (ERCC3) | TFIIH helicase; DNA unwinding | Mutations cause XP/CS; essential for NER |
| XPD (ERCC2) | TFIIH helicase; DNA unwinding | Mutations cause XP, CS, and TTD; target for point mutations |
| XPF (ERCC4) | 5' incision endonuclease | Defects cause XP and Fanconi anemia-like phenotypes |
| XPG (ERCC5) | 3' incision endonuclease | Mutations cause XP and CS; regulates incision |
| ERCC1 | Partner of XPF; 5' incision | Defects cause repair deficiency and progeria-like features |
| CSB (ERCC6) | TC-NER initiation | Mutations cause Cockayne syndrome; regulates transcription-coupled repair |
| CSA (ERCC8) | TC-NER initiation | Mutations cause Cockayne syndrome; regulates CSB |
| TFIIH subunits | Transcription and NER coupling | Regulates both transcription and repair |
| RPA | Stabilizes undamaged strand | Essential for NER complex assembly |
| PCNA | Repair synthesis clamp | Regulates polymerase recruitment |
| CUL4A | CRL4 ubiquitin ligase subunit | Regulates DDB2 and XPC stability |
| ALC1 (CHD1L) | Chromatin remodeler | Facilitates NER in chromatin |
| p53 | Transcription factor; regulates NER genes | Modulates NER capacity and apoptosis |
| BRCA1 | DNA damage response; NER regulation | Links NER to homologous recombination |
How Is regulation of nucleotide-excision repair Regulated?
The regulation of nucleotide-excision repair (GO:2000819) is itself controlled by multiple signaling pathways and post-translational modifications. The CRL4-DDB2 ubiquitin ligase regulates the stability and activity of DDB2 and XPC in response to UV damage. Phosphorylation of XPA by ATR and other kinases modulates its function in the pre-incision complex. Chromatin modifications, including histone acetylation and ubiquitination, regulate access of NER factors to lesions. Transcription-coupled NER is regulated by CSB and CSA, which coordinate RNA polymerase II stalling with repair. Additionally, p53 and other transcription factors regulate the expression of NER genes, influencing overall repair capacity.
regulation of nucleotide-excision repair and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| XPC | Xeroderma pigmentosum | Knockout in keratinocytes or fibroblasts; UV sensitivity assays |
| XPA | Xeroderma pigmentosum | Point mutations to mimic patient variants; NER assays |
| CSB (ERCC6) | Cockayne syndrome | Knockout in neurons; transcription-coupled repair assays |
| XPD (ERCC2) | XP/CS/TTD | Knock-in of patient mutations; helicase activity assays |
| ERCC1 | Progeria-like syndrome | Knockout in mice; ageing and repair studies |
Xeroderma pigmentosum and Cockayne syndrome
Mutations in NER genes such as XPC, XPA, XPB, XPD, XPF, XPG, CSB, and CSA cause xeroderma pigmentosum (XP), Cockayne syndrome (CS), or overlapping syndromes. XP patients exhibit extreme UV sensitivity and a thousand-fold increased risk of skin cancer, while CS is characterized by developmental defects, neurodegeneration, and premature ageing. These disorders underscore the critical importance of NER regulation for human health.
Cancer predisposition and chemotherapy resistance
Dysregulation of NER is linked to cancer predisposition and altered responses to chemotherapy. For example, reduced NER capacity increases sensitivity to platinum-based drugs, while enhanced NER activity can confer resistance. NER gene expression signatures are being explored as biomarkers for patient stratification. Targeting NER regulatory pathways is a promising strategy to overcome chemoresistance.
Ageing and neurodegeneration
Defects in NER regulation contribute to accelerated ageing phenotypes and neurodegeneration, as seen in Cockayne syndrome and some XP patients. Persistent DNA damage and transcription blockage trigger cellular senescence and apoptosis in post-mitotic neurons. Understanding NER regulation may provide insights into age-related diseases.
From regulation of nucleotide-excision repair-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate NER efficiency? | CRISPR knockout cell lines followed by UV survival and comet assays |
| Does a patient mutation in XPA affect repair? | Point-mutation knock-in via CRISPR |
| How does a regulatory protein localize to damage sites? | Tagged knock-in with fluorescent protein for live-cell imaging |
| Does overexpression of XPC enhance NER? | CRISPR activation or overexpression constructs |
| What are novel regulators of NER? | Genome-wide CRISPR library screening with UV selection |
| How does chromatin remodeling affect NER? | Knockout of chromatin remodelers and ChIP-seq |
How to Study the regulation of nucleotide-excision repair Process
| Method | What It Measures | Typical Application |
|---|---|---|
| UV survival assay | Cell viability after UV damage | Assessing NER capacity in knockout cells |
| Comet assay | DNA strand breaks and repair kinetics | Quantifying NER efficiency |
| Immunofluorescence for CPD/6-4PP | Removal of specific lesions | Monitoring repair in situ |
| ChIP-seq | Genome-wide binding of NER factors | Mapping damage recognition |
| Proteomics | Protein interactions and modifications | Identifying regulatory networks |
| CRISPR screen | Genes affecting UV sensitivity | Discovering novel NER regulators |
| Live-cell imaging | Real-time recruitment of NER factors | Studying dynamics of repair |
| RNA-seq | Transcriptional changes after damage | Identifying NER gene expression signatures |
UV survival and DNA damage assays
UV survival assays measure the ability of cells to survive UV-induced DNA damage, reflecting NER capacity. Comet assays and immunofluorescence for pyrimidine dimers or 6-4 photoproducts directly quantify repair kinetics. These methods are used to assess the impact of regulatory gene knockouts or mutations.
Chromatin immunoprecipitation and sequencing
ChIP-seq for NER factors such as XPC, XPA, or TFIIH can map their recruitment to damage sites genome-wide. This reveals how regulatory mechanisms influence damage recognition and repair efficiency. Combining ChIP-seq with UV irradiation provides a powerful approach to study NER regulation.
Proteomics and interactomics
Mass spectrometry-based proteomics can identify post-translational modifications and interaction partners of NER factors. This helps uncover regulatory networks and signaling pathways that modulate NER. Proximity labeling approaches can capture dynamic interactions at damage sites.
CRISPR screens and functional genomics
Genome-wide CRISPR knockout or activation screens coupled with UV or cisplatin selection can identify novel regulators of NER. These screens have revealed genes involved in chromatin remodeling, ubiquitination, and transcription. Follow-up validation with targeted knockouts confirms causal roles.
How CRISPR Can Be Used to Study GO:2000819 regulation of nucleotide-excision repair
Knockout
CRISPR knockout of NER regulatory genes such as XPC, XPA, or DDB2 is used to assess their requirement for repair. Knockout cell lines show increased UV sensitivity and reduced damage removal. These models are essential for validating gene function in NER.
Point Mutation
Point mutations that mimic patient variants in genes like XPA or XPD can be introduced via CRISPR to study their impact on NER. These models help dissect the molecular consequences of specific amino acid changes. They are valuable for understanding genotype-phenotype relationships.
Knock-in
Knock-in of tagged versions of NER proteins, such as GFP-XPC, allows live-cell imaging of repair dynamics. This approach reveals how regulatory modifications affect recruitment and turnover. Knock-in models are also used to express patient mutations under endogenous regulation.
Overexpression
Overexpression of NER factors like XPC or XPA can enhance repair capacity and confer resistance to DNA-damaging agents. These models are useful for studying the effects of increased NER on genome stability and chemotherapy response. They can also help identify rate-limiting steps in NER.
How EDITGENE Supports regulation of nucleotide-excision repair Research
Researchers studying regulation of nucleotide-excision repair-related genes often need to determine whether a candidate gene is causally involved in repair, how specific mutations affect protein function, and whether modulating its expression alters cellular sensitivity to DNA damage. EDITGENE provides a comprehensive suite of CRISPR-based services to address these questions with precision and reproducibility.
Contact EDITGENE today to design your custom CRISPR model for regulation of nucleotide-excision repair research.
Frequently Asked Questions About regulation of nucleotide-excision repair
What is GO:2000819?
GO:2000819 is the Gene Ontology term for regulation of nucleotide-excision repair, defined as any process that modulates the frequency, rate or extent of nucleotide-excision repair.
What genes are involved in regulation of nucleotide-excision repair?
Key genes include XPC, XPA, DDB2, XPB, XPD, XPF, XPG, ERCC1, CSB, CSA, and chromatin remodelers such as ALC1.
How is nucleotide-excision repair regulated?
NER is regulated at multiple levels, including damage recognition, chromatin remodeling, post-translational modifications, and transcription-coupled repair.
What diseases are linked to dysregulation of nucleotide-excision repair?
Dysregulation is linked to xeroderma pigmentosum, Cockayne syndrome, cancer predisposition, and chemotherapy resistance.
What are the subpathways of nucleotide-excision repair?
The two main subpathways are global-genome NER (GG-NER) and transcription-coupled NER (TC-NER).
How can CRISPR be used to study regulation of nucleotide-excision repair?
CRISPR knockout, point mutation, knock-in, and overexpression models allow functional dissection of NER regulatory genes.
What methods are used to measure nucleotide-excision repair activity?
Common methods include UV survival assays, comet assays, immunofluorescence for DNA lesions, and ChIP-seq.
What is the role of XPC in nucleotide-excision repair?
XPC is a damage recognition factor in GG-NER that initiates repair by binding to helix-distorting lesions.
How does chromatin remodeling affect nucleotide-excision repair?
Chromatin remodeling facilitates access of NER factors to lesions and is regulated by histone modifications and ATP-dependent remodelers.
Why is regulation of nucleotide-excision repair important for cancer therapy?
NER capacity influences sensitivity to platinum-based drugs and radiotherapy, making its regulators potential therapeutic targets.
Conclusion
GO:2000819 (regulation of nucleotide-excision repair) represents a critical layer of genome maintenance that controls how cells detect and remove bulky DNA lesions. The regulatory mechanisms involve a complex interplay of damage recognition factors, chromatin remodelers, post-translational modifications, and transcription-coupled repair. Dysregulation of these processes underlies several human diseases, including xeroderma pigmentosum, Cockayne syndrome, and cancer. Continued research using CRISPR-based models and advanced genomics will further illuminate how NER is regulated and how these insights can be translated into therapeutic strategies.
References
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- 3. Kusakabe M et al.. 2019. Mechanism and regulation of DNA damage recognition in nucleotide excision repair.. Genes Environ 41:2 PMID: 30700997
- 4. Marteijn JA et al.. 2014. Understanding nucleotide excision repair and its roles in cancer and ageing.. Nat Rev Mol Cell Biol 15(7):465-81 PMID: 24954209
- 5. Sugasawa K. 2019. Mechanism and regulation of DNA damage recognition in mammalian nucleotide excision repair.. Enzymes 45:99-138 PMID: 31627884
- 6. Jarrett SG et al.. 2017. Paracrine regulation of melanocyte genomic stability: a focus on nucleotide excision repair.. Pigment Cell Melanoma Res 30(3):284-293 PMID: 28192636
- 7. Hanawalt PC. 2002. Subpathways of nucleotide excision repair and their regulation.. Oncogene 21(58):8949-56 PMID: 12483511
- 8. Fagbemi AF et al.. 2011. Regulation of endonuclease activity in human nucleotide excision repair.. DNA Repair (Amst) 10(7):722-9 PMID: 21592868
