Inactivation of Saccharomyces cerevisiae OGG1 DNA repair gene leads to an increased frequency of mitochondrial mutants.
نویسندگان
چکیده
The OGG1 gene encodes a highly conserved DNA glycosylase that repairs oxidized guanines in DNA. We have investigated the in vivo function of the Ogg1 protein in yeast mitochondria. We demonstrate that inactivation of ogg1 leads to at least a 2-fold increase in production of spontaneous mitochondrial mutants compared with wild-type. Using green fluorescent protein (GFP) we show that a GFP-Ogg1 fusion protein is transported to mitochondria. However, deletion of the first 11 amino acids from the N-terminus abolishes the transport of the GFP-Ogg1 fusion protein into the mitochondria. This analysis indicates that the N-terminus of Ogg1 contains the mitochondrial localization signal. We provide evidence that both yeast and human Ogg1 proteins protect the mitochondrial genome from spontaneous, as well as induced, oxidative damage. Genetic analyses revealed that the combined inactivation of OGG1 and OGG2 [encoding an isoform of the Ogg1 protein, also known as endonuclease three-like glycosylase I (Ntg1)] leads to suppression of spontaneously arising mutations in the mitochondrial genome when compared with the ogg1 single mutant or the wild-type. Together, these studies provide in vivo evidence for the repair of oxidative lesions in the mitochondrial genome by human and yeast Ogg1 proteins. Our study also identifies Ogg2 as a suppressor of oxidative mutagenesis in mitochondria.
منابع مشابه
OGG1 DNA Repair Gene Polymorphism As a Biomarker of Oxidative and Genotoxic DNA Damage
Background: Single nucleotide polymorphisms in 8-oxoguanine DNA glycosylase-1 (OGG1) gene modulates DNA repair capacity and functions as one of the first lines of protective mechanisms against 8-hydroxy-2’-deoxyguanosine (8-OHdG) mutagenicity. OGG1-Cys326 gene polymorphism may decrease DNA repair function, causing oxidative stress due to higher oxidative DNA damage. The main purpose of this stu...
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ورودعنوان ژورنال:
- Nucleic acids research
دوره 29 6 شماره
صفحات -
تاریخ انتشار 2001