UV irradiation induces a postreplication DNA damage checkpoint

摘要: Eukaryotic cells irradiated with high doses of UV exhibit cell-cycle responses referred to as G1/S, intraS, and G2/M checkpoints. After a moderate dose that approximates sunlight exposure is lethal fission yeast checkpoint mutants, we found unexpectedly these do not occur. Instead, at all stages the cell cycle carry lesions into S phase delay progression for hours after completion bulk DNA synthesis. Both replication kinase, Chk1, are required generate this response. UV-irradiation Δchk1 causes chromosome damage loss viability only have replicated entered mitosis. These data suggest an important physiological role response provide time postreplication repair.