Checkpoint kinase phosphorylation in response to endogenous oxidative DNA damage in repair-deficient stationary-phase Saccharomyces cerevisiae.

ABSTRACT: Stationary-phase Saccharomyces cerevisiae can serve as a model for post-mitotic cells of higher eukaryotes. Phosphorylation and activation of the checkpoint kinase Rad53 was observed after more than 2 days of culture if two major pathways of oxidative DNA damage repair, base excision repair (BER) and nucleotide excision repair (NER), are inactive. The wild type showed a low degree of Rad53 phosphorylation when the incubation period was drastically increased. In the ber ner strain, Rad53 phosphorylation can be abolished by inclusion of antioxidants or exclusion of oxygen. Furthermore, this modification and enhanced mutagenesis in extended stationary phase were absent in rho degrees strains, lacking detectable mitochondrial DNA. This checkpoint response is therefore thought to be dependent o

SUBMITTER: Pawar V 

PROVIDER: S-EPMC2716406 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature