A single unbranched S-phase DNA damage and replication fork blockage checkpoint pathway

摘要

The eukaryotic intra-S-phase checkpoint, which slows DNA syn- thesis in response to DNA damage, is poorly understood. Is DNA damage recognized directly, or indirectly through its effects on replication forks? Is the slowing of S phase in part because of competition between DNA synthesis and recombination/repair processes? The results of our genetic analyses of the intra-S-phase checkpoint in the fission yeast, Schizosaccharomyces pombe, sug- gest that the slowing of S phase depends weakly on the helicases Rqh1 and Srs2 but not on other recombination/repair pathways.