Mutations in the gene aprataxin (APTX) are responsible for the rare neurological disorder ataxia oculomotor apraxia-1 (AOA1). Stephen West and his colleagues show in a paper published online by Nature that this protein is involved in DNA repair, and suggest that AOA1 may be caused by the gradual accumulation of unrepaired breaks in the DNA of neuronal cells.
Aprataxin associates with other DNA repair proteins, but it was not known whether it has a direct role in the process of DNA repair. The researchers used purified extracts containing normal and mutant aprataxin protein to show that the protein helps join together double-strand breaks in DNA induced by reactive oxygen molecules, or free radicals. Specifically, it removes chemical groups called adenylates from one of the DNA ends to allow them to be stitched back together.
Stephen West (Cancer Research UK, London, UK)
(C) Nature press release.
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