Isolation and characterization of point mutations in mismatch repair genes that destabilize microsatellites in yeast.
The stability of simple repetitive DNA sequences (microsatellites) is a sensitive indicator of the ability of a cell to repair DNA mismatches. In a genetic screen for yeast mutants with elevated microsatellite instability, we identified strains containing point mutations in the yeast mismatch repair genes, MSH2, MSH3, MLH1, and PMS1. Some of these mutations conferred phenotypes significantly different from those of null mutations in these genes. One semidominant MSH2 mutation was identified. Finally we showed that strains heterozygous for null mutations of mismatch repair genes in diploid strains in yeast confer subtle defects in the repair of small DNA loops.
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Department of Biology, University of Rochester, Rochester, New York 14627-0211, USA.
Dominska
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Stefanovic
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Petes
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D048868:Adaptor Proteins, Signal Transducing; D020137:Base Pair Mismatch / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics; D004260:DNA Repair / Q000502:physiology*; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D004171:Diploidy; D005656:Fungal Proteins / Q000235:genetics; D005799:Genes, Dominant; D006579:Heterozygote; D018895:Microsatellite Repeats / Q000502:physiology*; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D051718:MutS Homolog 2 Protein; D000074081:MutS Homolog 3 Protein; D016296:Mutagenesis; D010641:Phenotype; D017354:Point Mutation; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C088859:MLH1 protein, S cerevisiae; C081696:MSH3 protein, S cerevisiae; D000074081:MutS Homolog 3 Protein; C088858:PMS1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C489751:MSH2 protein, S cerevisiae; D000070957:MutL Protein Homolog 1; D000070956:MutL Proteins; D051718:MutS Homolog 2 Protein