OGG1 initiates age-dependent CAG trinucleotide expansion in somatic cells

Irina V. Kovtun, Yuan Liu, Magnar Bjoras, Arne Klungland, Samuel H. Wilson, Cynthia T. McMurray

Research output: Contribution to journalArticlepeer-review

328 Scopus citations


Although oxidative damage has long been associated with ageing and neurological disease, mechanistic connections of oxidation to these phenotypes have remained elusive. Here we show that the age-dependent somatic mutation associated with Huntington's disease occurs in the process of removing oxidized base lesions, and is remarkably dependent on a single base excision repair enzyme, 7,8-dihydro-8-oxoguanine-DNA glycosylase (OGG1). Both in vivo and in vitro results support a 'toxic oxidation' model in which OGG1 initiates an escalating oxidation-excision cycle that leads to progressive age-dependent expansion. Age-dependent CAG expansion provides a direct molecular link between oxidative damage and toxicity in post-mitotic neurons through a DNA damage response, and error-prone repair of single-strand breaks.

Original languageEnglish (US)
Pages (from-to)447-452
Number of pages6
Issue number7143
StatePublished - May 24 2007

ASJC Scopus subject areas

  • General


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