XPA Gene
XPA, DNA Damage Recognition and Repair Factor
Gene Information Card
| Symbol | XPA |
|---|---|
| Full Name | XPA, DNA damage recognition and repair factor |
| Gene Type | Protein coding |
| Chromosomal Location | 9q22.33 |
| NCBI Gene ID | 7507 ncbi.nlm.nih.gov/gene/7507 |
| Ensembl ID | ENSG00000136936 |
| UniProt ID | P23025 |
| OMIM ID | 278700 |
| HGNC ID | 12814 |
| Aliases | XPAC, XP1 |
Description
The XPA gene encodes a zinc-finger protein involved in the nucleotide excision repair (NER) pathway. It recognizes and binds to damaged DNA, recruiting other repair factors to remove UV-induced photoproducts and other bulky adducts. Mutations in XPA cause xeroderma pigmentosum complementation group A, a disorder characterized by extreme sensitivity to sunlight and high risk of skin cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Xeroderma Pigmentosum, Group A | Loss of XPA function impairs NER, leading to accumulation of UV-induced DNA damage and increased mutagenesis. | OMIM #278700; ClinVar |
| Skin Cancer (Melanoma and Non-melanoma) | Defective DNA repair in XPA patients results in high mutation rates in skin cells, promoting carcinogenesis. | COSMIC; NCBI Gene |
| Xeroderma Pigmentosum with Neurologic Abnormalities | Some XPA mutations cause severe NER deficiency, leading to neurodegeneration due to unrepaired DNA damage in neurons. | OMIM #278700 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skin | 12.5 | Medium |
| Testis | 10.2 | Medium |
| Lung | 8.1 | Low |
| Brain | 6.3 | Low |
| Liver | 5.9 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.3 | Cervical cancer cell line |
| A549 | 11.8 | Lung carcinoma cell line |
| HEK293 | 9.4 | Embryonic kidney cell line |
| MCF7 | 7.2 | Breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.682C>T (p.Arg228Ter) | Nonsense | Common in Japanese XP-A patients | Loss of function; truncated protein |
| c.555+1G>A | Splice site | Found in European XP-A patients | Splicing defect; loss of function |
| c.349A>G (p.Lys117Glu) | Missense | Rare | Impaired DNA binding; reduced repair activity |
Mutation functional classification
Loss of Function (LOF)
Most XPA mutations cause loss of function by truncating the protein or disrupting its DNA-binding domain, leading to defective NER.
Gain of Function (GOF)
No gain-of-function mutations reported for XPA.
Dominant Negative (DN)
No dominant-negative mutations reported; XPA deficiency is recessive.
View complete mutation data：
Gene Ontology (GO)
| • GO:0003684 - damaged DNA binding | • GO:0006289 - nucleotide-excision repair |
| • GO:0005515 - protein binding | • GO:0005634 - nucleus |
Pathways
• Nucleotide Excision Repair (hsa03420)
• p53 signaling pathway (hsa04115)
Protein Summary
The XPA protein (273 amino acids, ~31 kDa) contains a central DNA-binding domain with a zinc-finger motif. It interacts with RPA, ERCC1, and TFIIH to verify DNA damage and position the repair machinery. XPA is essential for global genome and transcription-coupled NER.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| XPA Knockout HEK293 Cell Line | EDJ-KQ5295 | Human | 7507 | Details Get a Quote |
| XPA Knockout A-549 Cell Line | EDJ-KQ29630 | Human | 7507 | Details Get a Quote |
| XPA Knockout HCT 116 Cell Line | EDJ-KQ29632 | Human | 7507 | Details Get a Quote |
| XPA Knockout HeLa Cell Line | EDJ-KQ29633 | Human | 7507 | Details Get a Quote |
| XPA Knockout HAP1 Cell Line | EDC08036 | Human | 7507 | Details Get a Quote |
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