Elevated dNTP levels suppress hyper-recombination in Saccharomyces cerevisiae S-phase checkpoint mutants.

ABSTRACT: MEC1, the essential yeast homolog of the human ATR/ATM genes, controls the S-phase checkpoint and prevents replication fork collapse at slow zones of DNA replication. The viability of hypomorphic mec1-21 is reduced in the rad52 mutant, defective in homologous recombination, suggesting that replication generates recombinogenic lesions. We previously observed a 6-, 10- and 30-fold higher rate of spontaneous sister chromatid exchange (SCE), heteroallelic recombination and translocations, respectively, in mec1-21 mutants compared to wild-type. Here we report that the hyper-recombination phenotype correlates with lower deoxyribonucleoside triphosphate (dNTP) levels, compared to wild-type. By introducing a dun1 mutation, thus eliminating inducible expression of ribonucleotide reductase in mec1-2

SUBMITTER: Fasullo M 

PROVIDER: S-EPMC2831302 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature