Aprataxin

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title: "Aprataxin" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public description: "Protein-coding gene in the species Homo sapiens" topic_path: "uncategorized" source: "https://en.wikipedia.org/wiki/Aprataxin" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Protein-coding gene in the species Homo sapiens ::

Aprataxin is a protein that in humans is encoded by the APTX gene.

This gene encodes a member of the histidine triad (HIT) superfamily, some of which have nucleotide-binding and diadenosine polyphosphate hydrolase activities. The encoded protein may play a role in single-stranded DNA repair. Mutations in this gene have been associated with ataxia–ocular apraxia. Multiple transcript variants encoding distinct isoforms have been identified for this gene, however, the full length nature of some variants has not been determined.

Function

Aprataxin removes AMP from DNA ends following abortive ligation attempts by DNA Ligase IV during non-homologous end joining, thereby permitting subsequent attempts at ligation.

DNA strand breaks

Ataxia oculomotor apraxia-1 is a neurological disorder caused by mutations in the APTX gene that encodes aprataxin. The neurological disorder appears to be caused by the gradual accumulation of unrepaired DNA strand breaks resulting from abortive DNA ligation events.

Premature aging

Aptx−/− mutant mice have been generated, but they lack an obvious phenotype. The SOD1 mutation causes a reduction in transcription recovery following oxidative stress. These mice showed accelerated cellular senescence. This study also demonstrated a protective role of Aptx in vivo and suggested that the loss of Aptx function results in progressive accumulation of DNA breaks in the nervous system, triggering hallmarks of systemic premature aging (see DNA damage theory of aging).

Interactions

Aprataxin has been shown to interact with:

• PARP1,
• P53,
• XRCC1, and
• XRCC4.

References

References

1. (Oct 2001). "Early-onset ataxia with ocular motor apraxia and hypoalbuminemia is caused by mutations in a new HIT superfamily gene". Nat Genet.
2. (Oct 2001). "The gene mutated in ataxia-ocular apraxia 1 encodes the new HIT/Zn-finger protein aprataxin". Nat Genet.
3. "Entrez Gene: APTX aprataxin".
4. (December 2008). "Molecular mechanism of DNA deadenylation by the neurological disease protein aprataxin". J. Biol. Chem..
5. (March 2009). "Defective DNA ligation during short-patch single-strand break repair in ataxia oculomotor apraxia 1". Mol. Cell. Biol..
6. (2006). "The neurodegenerative disease protein aprataxin resolves abortive DNA ligation intermediates". Nature.
7. (2015). "Expression of a pathogenic mutation of SOD1 sensitizes aprataxin-deficient cells and mice to oxidative stress and triggers hallmarks of premature ageing". Hum. Mol. Genet..
8. (December 2004). "The FHA domain of aprataxin interacts with the C-terminal region of XRCC1". Biochem. Biophys. Res. Commun..
9. (May 2004). "Aprataxin, a novel protein that protects against genotoxic stress". Hum. Mol. Genet..
10. (November 2004). "The ataxia-oculomotor apraxia 1 gene product has a role distinct from ATM and interacts with the DNA strand break repair proteins XRCC1 and XRCC4". DNA Repair (Amst.).

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