APTX (Aprataxin) Gene
A key gene in DNA single-strand break repair, associated with ataxia and neurological disorders.
Gene Information Card
| Symbol | APTX |
|---|---|
| Full Name | Aprataxin |
| Gene Type | Protein coding |
| Chromosomal Location | 9p21.1 |
| NCBI Gene ID | 54840 ncbi.nlm.nih.gov/gene/54840 |
| Ensembl ID | ENSG00000169093 |
| UniProt ID | Q7Z2Y3 |
| OMIM ID | 606350 |
| HGNC ID | 15984 |
| Aliases | AOA1, EAOH, EOAHA, FHA-HIT |
Description
The APTX gene encodes aprataxin, a protein involved in single-strand DNA break repair. It processes 5'-adenylate and 3'-phosphate termini generated by abortive ligation events, restoring ligatable ends. Mutations in APTX cause ataxia with oculomotor apraxia type 1 (AOA1), a neurodegenerative disorder characterized by cerebellar ataxia, oculomotor apraxia, and peripheral neuropathy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Ataxia with oculomotor apraxia type 1 (AOA1) | Loss of aprataxin function impairs DNA single-strand break repair, leading to accumulation of DNA damage and neuronal death. | OMIM #208920; ClinVar; multiple publications |
| Early-onset ataxia with oculomotor apraxia and hypoalbuminemia (EAOH) | Same mechanism as AOA1; hypoalbuminemia is a distinguishing feature. | OMIM #208920; ClinVar |
| Spinocerebellar ataxia, autosomal recessive (SCAR) | Some APTX mutations cause a broader ataxia phenotype without oculomotor apraxia. | ClinVar; literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 5.2 | Low |
| Cerebellum | 6.8 | Low |
| Heart | 4.1 | Low |
| Liver | 3.5 | Low |
| Testis | 8.9 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 6.3 | Embryonic kidney cells |
| HeLa | 5.1 | Cervical cancer cells |
| SH-SY5Y | 7.2 | Neuroblastoma cells |
| U-87 MG | 4.8 | Glioblastoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.689C>T (p.Pro230Leu) | Missense | Common in AOA1 | Reduced protein stability and enzymatic activity |
| c.837G>A (p.Trp279*) | Nonsense | Rare | Premature truncation, loss of function |
| c.502C>T (p.Arg168Cys) | Missense | Rare | Impaired DNA binding |
| c.641_642del (p.Lys214Argfs*2) | Frameshift | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Most APTX mutations result in loss of aprataxin enzymatic activity or protein stability, leading to defective DNA single-strand break repair.
Gain of Function (GOF)
No evidence of gain-of-function mutations in APTX.
Dominant Negative (DN)
No evidence of dominant-negative effects; APTX-associated disorders are autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• DNA single-strand break repair (Reactome: R-HSA-73928)
• Base excision repair (Reactome: R-HSA-73884)
Protein Summary
Aprataxin is a 342-amino acid protein with an N-terminal forkhead-associated (FHA) domain, a central histidine triad (HIT) domain, and a C-terminal zinc finger. It specifically removes 5'-adenylate groups (AMP) from DNA ends generated by abortive ligation, and also exhibits 3'-phosphatase activity. The protein localizes to the nucleus and interacts with XRCC1 and other DNA repair factors.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| APTX Knockout HEK293 Cell Line | EDJ-KQ12398 | Human | 54840 | Details Get a Quote |
| APTX Knockout HeLa Cell Line | EDJ-KQ40015 | Human | 54840 | Details Get a Quote |
| APTX Knockout A-549 Cell Line | EDJ-KQ41284 | Human | 54840 | Details Get a Quote |
| APTX Knockout HCT 116 Cell Line | EDJ-KQ41285 | Human | 54840 | Details Get a Quote |
| APTX Knockout HAP1 Cell Line | EDC08164 | Human | 54840 | Details Get a Quote |
