| Title: | "Suppression of a new allele of the yeast RAD52 gene by overexpression of RAD51, mutations in srs2 and ccr4, or mating-type heterozygosity" |
| Address: | "Life Sciences Division, Lawrence Berkeley Laboratory, California 94720, USA" |
| DOI: | 10.1093/genetics/140.1.115 |
| ISSN/ISBN: | 0016-6731 (Print) 0016-6731 (Linking) |
| Abstract: | "The RAD52 gene of Saccharomyces cerevisiae is involved both in the recombinational repair of DNA damage and in mitotic and meiotic recombination. A new allele of rad52 has been isolated that has unusual properties. Unlike other alleles of rad52, this allele (rad52-20) is partially suppressed by an srs2 deletion; srs2 mutations normally act to suppress only rad6 and rad18 mutations. In addition, although haploid rad52-20 strains are very X-ray sensitive, diploids homozygous for this allele are only slightly X-ray sensitive and undergo normal meiosis and meiotic recombination. Because rad52-20 diploids homozygous for mating type are very X-ray sensitive, mating-type heterozygosity is acting to suppress rad52-20. Mating-type heterozygosity suppresses this allele even in haploids, because sir mutations, which result in expression of the normally silent mating-type cassettes, were identified among the extragenic revertants of rad52-20. A new allele of srs2 and alleles of the transcriptional regulatory genes ccr4 and caf1 were among the other extragenic revertants of rad52-20. Because other researchers have shown that the RAD51 and RAD52 proteins interact, RAD51 on a high copy number plasmid was tested and found to suppress the rad52-20 allele, but RAD54, 55 and 57 did not suppress. The RAD51 plasmid did not suppress rad52-1. The rad52-20 allele may encode a protein that has low affinity binding to the RAD51 protein. To test whether the selected revertants suppressed rad52-20 by elevating the expression of RAD51, an integrated RAD51-lacZ fusion was genetically crossed into each revertant. Because none of the revertants increased the level of RAD51-lacZ, the revertants must exert their effect by one or more mechanisms that are not mediated by RAD51" |
| Keywords: | "*Alleles DNA Helicases/*genetics DNA-Binding Proteins/genetics Fungal Proteins/*genetics *Gene Expression Regulation, Fungal/radiation effects *Genes, Fungal Heterozygote *Histone Deacetylases *Homeodomain Proteins Mating Factor Peptides/genetics Radiatio;" |
| Notes: | "MedlineSchild, D eng GM-30990/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 1995/05/01 Genetics. 1995 May; 140(1):115-27. doi: 10.1093/genetics/140.1.115" |
