Deletion of Ogg1 DNA glycosylase results in telomere base damage and length alteration in yeast

Jian Lu, Yie Liu

Research output: Contribution to journalArticle

Abstract

Telomeres consist of short guanine-rich repeats. Guanine can be oxidized to 8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5- formamidopyrimidine (FapyG). 8-oxoguanine DNA glycosylase (Ogg1) repairs these oxidative guanine lesions through the base excision repair (BER) pathway. Here we show that in Saccharomyces cerevisiae ablation of Ogg1p leads to an increase in oxidized guanine level in telomeric DNA. The ogg1 deletion (ogg1Δ) strain shows telomere lengthening that is dependent on telomerase and/or Rad52p-mediated homologous recombination. 8-oxoG in telomeric repeats attenuates the binding of the telomere binding protein, Rap1p, to telomeric DNA in vitro. Moreover, the amount of telomere-bound Rap1p and Rif2p is reduced in ogg1Δ strain. These results suggest that oxidized guanines may perturb telomere length equilibrium by attenuating telomere protein complex to function in telomeres, which in turn impedes their regulation of pathways engaged in telomere length maintenance. We propose that Ogg1p is critical in maintaining telomere length homoeostasis through telomere guanine damage repair, and that interfering with telomere length homoeostasis may be one of the mechanism(s) by which oxidative DNA damage inflicts the genome.

Original languageEnglish (US)
Pages (from-to)398-409
Number of pages12
JournalEMBO Journal
Volume29
Issue number2
DOIs
Publication statusPublished - Jan 2010
Externally publishedYes

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Keywords

  • DNA glycosylase
  • Oxidative guanine lesion telomere length

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Immunology and Microbiology(all)
  • Biochemistry, Genetics and Molecular Biology(all)

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