Genetic control of excision of Saccharomyces cerevisiae interstrand DNA cross-links induced by psoralen plus near-UV light.
Excision of interstrand DNA cross-links induced by 4,5',8-trimethyl psoralen plus 360-nm light was examined in wild type (RAD+) and various radiation-sensitive (rad) mutants of Saccharomyces cerevisiae known to be defective in the excision of UV light-induced pyrimidine dimers. Alkaline sucrose sedimentation of DNA after incubation of psoralen-plus-light-treated cells indicated little or no nicking of cross-linked DNA in rad1-2, rad2-5, rad3-2, rad4-4, rad10-2, and mms19-1 mutants. In the rad14-2 mutant, substantial nicking was observed but to a much lesser extent than in the RAD+ strains, whereas the rad16-1 mutant was as proficient in nicking as the RAD+ strain. Removal of cross-links was also examined in RAD+, rad3-2, and rad14-2 strains by determining the sensitivity of alkali-denatured and -neutralized DNA to hydrolysis by S1 nuclease. No cross-link removal was observed in the rad3-2 mutants, and the rad14-2 mutant was much less efficient than the RAD+ strain in removing cross-links.
D004260:DNA Repair; D004271:DNA, Fungal / Q000378:metabolism*; D011564:Furocoumarins / Q000494:pharmacology*; D008954:Models, Biological; D009154:Mutation; D011740:Pyrimidine Dimers / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D014307:Trioxsalen / Q000494:pharmacology*; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D011564:Furocoumarins; D011740:Pyrimidine Dimers; D014307:Trioxsalen