ERCC3 Gene
Overview
Mermaid diagram (expand to render)
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">ERCC3 Gene</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>ERCC3</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>ERCC3</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Gene</td>
</tr>
<tr>
<td class="label">NCBI</td>
<td><a href="https://www.ncbi.nlm.nih.gov/gene/?term=ERCC3" target="_blank">Search NCBI</a></td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a>, <a href="/wiki/cirrhosis" style="color:#ef9a9a">Cirrhosis</a>, <a href="/wiki/hepatocellular-carcinoma" style="color:#ef9a9a">Hepatocellular Carcinoma</a></td>
</tr>
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<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">35 edges</a></td>
</tr>
</table>
ERCC3 (Excision Repair Cross-Complementation Group 3), also known as TFIIH core component, is a DNA repair gene located on chromosome 19q13.32. The protein encodes a DNA helicase subunit of the transcription factor IIH (TFIIH) complex, which is essential for both transcription initiation and nucleotide excision repair (NER). ERCC3 plays a critical role in transcription-coupled nucleotide excision repair (TC-NER), a pathway that specifically repairs DNA lesions in actively transcribed genes.
Gene and Protein Structure
The ERCC3 gene spans approximately 15 kb and consists of 17 exons. It encodes a 782-amino acid protein with a molecular weight of approximately 89 kDa. The protein contains seven conserved motifs characteristic of the SF2 helicase family, including the ATP-dependent DNA helicase domain. ERCC3 forms a core component of the TFIIH complex, which contains both repair and transcription activities. [@weinberg2019]
Normal Function in the Nervous System
In the nervous system, ERCC3/TFIIH is essential for: [@kroker2014]
- Transcription initiation: ERCC3's helicase activity unwinds DNA at the promoter region, allowing RNA polymerase II to initiate transcription of neuronal genes
- DNA repair: TC-NER removes bulky DNA lesions (UV-induced pyrimidine dimers, chemical adducts) that would otherwise block transcription
- Neuronal survival: Proper DNA repair maintains genomic integrity in post-mitotic [neurons](/entities/neurons), which cannot undergo replication-based repair
Neurons are particularly dependent on TC-NER due to their high metabolic rate, oxidative stress exposure, and inability to replicate. [@scarolla2022]
Role in Neurodegenerative Diseases
Cockayne Syndrome
Biallelic mutations in ERCC3 cause Cockayne syndrome (CS), a rare autosomal recessive disorder characterized by progressive neurodegeneration, developmental delay, photosensitivity, and premature aging. CS patients exhibit: [@t2007]
- Severe neurological impairment with intellectual disability
- Cerebellar ataxia and motor dysfunction
- Peripheral neuropathy
- Cachexia
- Early onset neurodegeneration
CS is considered a segmental progeroid syndrome, sharing features with accelerated aging, including neurodegeneration.
Alzheimer's Disease
ERCC3 polymorphisms have been associated with [Alzheimer's disease](/diseases/alzheimers-disease) (AD) risk in genome-wide association studies (GWAS). The DNA repair capacity declines with age, and impaired TC-NER may contribute to:
- Accumulation of DNA damage in neurons
- Dysregulation of transcription of synaptic proteins
- Activation of DNA damage response pathways
- [Neuroinflammation](/mechanisms/neuroinflammation)
Parkinson's Disease
Evidence suggests ERCC3 variants may modify [Parkinson's disease](/diseases/parkinsons-disease) (PD) risk. DNA repair mechanisms are crucial for maintaining dopaminergic neuron viability, as these cells face high oxidative stress from dopamine metabolism.
Therapeutic Implications
ERCC3 and the TFIIH complex represent potential therapeutic targets:
- Gene therapy: Delivering functional ERCC3 to neurons in CS patients
- Small molecule modulators: Enhancing TFIIH activity to improve DNA repair
- Antioxidant therapies: Reducing oxidative DNA damage burden
- Neuroprotective strategies: Supporting neuronal DNA repair capacity
Expression Patterns
ERCC3 is ubiquitously expressed in all human tissues, including:
- Brain: neurons, [astrocytes](/entities/astrocytes), [microglia](/cell-types/microglia-neuroinflammation), oligodendrocytes
- Highest expression in regions with high metabolic activity
- Expression decreases with age in brain tissue
Interactions and Pathways
ERCC3 interacts with:
- TFIIH complex: Core component (XPB, p62, p52, p44, p34, p8)
- CSA (ERCC8): Cockayne syndrome type A protein
- CSB (ERCC6): Cockayne syndrome type B protein
- RNA polymerase II: Co-transcriptional recruitment
- XPA, XPC: NER pathway proteins
Summary
ERCC3 is a critical DNA repair and transcription gene whose dysfunction leads to severe neurodegenerative phenotypes. Its role in maintaining genomic integrity in post-mitotic neurons makes it relevant to age-related neurodegenerative diseases including AD and PD.
- [DNA Repair Pathways](/mechanisms/dna-damage-response-neurodegeneration) Syndrome
- [DNA Repair Pathways](/mechanisms/dna-damage-response-neurodegeneration) TFIIH Complex
- Nucleotide Excision Repair
- Transcription-Coupled Repair
- Aging and [Neurodegeneration](/diseases/neurodegeneration)
External Links
- [NCBI Gene: ERCC3](https://www.ncbi.nlm.nih.gov/gene/2075)
- [OMIM: ERCC3](https://www.omim.org/entry/133510)
- [UniProt: ERCC3](https://www.uniprot.org/uniprot/P19447)
References
[Faghri et al., ERCC3 mutations in Cockayne syndrome (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29361024/)
[Weinberg et al., TFIIH and transcription-coupled repair (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31199387/)
[Kroker et al., ERCC3 polymorphisms and Alzheimer's disease risk (2014) (2014)](https://pubmed.ncbi.nlm.nih.gov/24526841/)
[Scarolla et al., DNA repair in neurodegenerative diseases (2022) (2022)](https://pubmed.ncbi.nlm.nih.gov/35894223/)
[T Chestovich et al., TFIIH functions in brain development (2007) (2007)](https://pubmed.ncbi.nlm.nih.gov/17535976/)Pathway Diagram
The following diagram shows the key molecular relationships involving ERCC3 Gene discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)