Mutations in RAD3, MSH2, and RAD52 affect the rate of gene amplification in the yeast Saccharomyces cerevisiae.
We report here the use of the ADH4:CUP1 amplification detection system to identify five high amplification rate (HAR) strains of Saccharomyces cerevisiae that display 40- to 600-fold higher amplification rates than those of parental strains. We have identified a mutation in RAD3 DNA repair helicase gene in HAR strain B9-40 that results in a 40-fold increase in amplification rate. RAD3 is the functional homolog of the human XPD gene, suggesting that this model system will provide important candidates for genes that affect gene amplification in human cells. Isolation of the HAR strains has allowed us to test whether RAD52, which is essential for recombinational repair of DNA double-strand breaks, is also essential for amplification. Deletion of RAD52 in HAR strains B3-10 and B11-60 decreases amplification approximately 100-fold. In contrast, deletion of MSH2, which increases recombination between sequences with limited similarity, increases the amplification rate about 10-fold. These results suggest that recombination is an important step in amplification.
Peterson
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C
Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio 45221-0006, USA.
Kordich
J
J
Milligan
L
L
Bodor
E
E
Siner
A
A
Nagy
K
K
Paquin
C E
CE
D000251:Adenosine Triphosphatases / Q000235:genetics*; D003001:Cloning, Molecular; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics*; D004271:DNA, Fungal / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000235:genetics*; D005784:Gene Amplification; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D051718:MutS Homolog 2 Protein; D016296:Mutagenesis; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051721:Rad52 DNA Repair and Recombination Protein; D011836:Radiation Tolerance / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; D008741:Methyl Methanesulfonate; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D051718:MutS Homolog 2 Protein; D004265:DNA Helicases