DNA polymerases required for repair of UV-induced damage in Saccharomyces cerevisiae.
The ability of yeast DNA polymerase mutant strains to carry out repair synthesis after UV irradiation was studied by analysis of postirradiation molecular weight changes in cellular DNA. Neither DNA polymerase alpha, delta, epsilon, nor Rev3 single mutants evidenced a defect in repair. A mutant defective in all four of these DNA polymerases, however, showed accumulation of single-strand breaks, indicating defective repair. Pairwise combination of polymerase mutations revealed a repair defect only in DNA polymerase delta and epsilon double mutants. The extent of repair in the double mutant was no greater than that in the quadruple mutant, suggesting that DNA polymerases alpha and Rev3p play very minor, if any, roles. Taken together, the data suggest that DNA polymerases delta and epsilon are both potentially able to perform repair synthesis and that in the absence of one, the other can efficiently substitute. Thus, two of the DNA polymerases involved in DNA replication are also involved in DNA repair, adding to the accumulating evidence that the two processes are coupled.
Budd
M E
ME
Braun Laboratories, California Institute of Technology, Pasadena 91125.
Campbell
J L
JL
D004249:DNA Damage; D004257:DNA Polymerase II; D004258:DNA Polymerase III; D004260:DNA Repair / Q000502:physiology*; D004271:DNA, Fungal / Q000528:radiation effects*; D004277:DNA, Single-Stranded / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D014466:Ultraviolet Rays / Q000009:adverse effects
D004271:DNA, Fungal; D004277:DNA, Single-Stranded; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D004257:DNA Polymerase II; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; C092602:REV3 protein, S cerevisiae