Suppression of a New Allele of the Yeast RAD52 Gene by Overexpression of RAD51, Mutations in srs2 and ccr4, or Mating-Type Heterozygosity

INVESTIGATIONS

Suppression of a New Allele of the Yeast RAD52 Gene by Overexpression of RAD51, Mutations in srs2 and ccr4, or Mating-Type Heterozygosity

D. Schild
Life Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720

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.

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				S. Van Komen, M. S. Reddy, L. Krejci, H. Klein, and P. Sung ATPase and DNA Helicase Activities of the Saccharomyces cerevisiae Anti-recombinase Srs2 J. Biol. Chem., November 7, 2003; 278(45): 44331 - 44337. [Abstract] [Full Text] [PDF]

				J. E. Lowell, A. I. Roughton, V. Lundblad, and L. Pillus Telomerase-Independent Proliferation Is Influenced by Cell Type in Saccharomyces cerevisiae Genetics, July 1, 2003; 164(3): 909 - 921. [Abstract] [Full Text] [PDF]

				N. J. Morey, P. W. Doetsch, and S. Jinks-Robertson Delineating the Requirements for Spontaneous DNA Damage Resistance Pathways in Genome Maintenance and Viability in Saccharomyces cerevisiae Genetics, June 1, 2003; 164(2): 443 - 455. [Abstract] [Full Text] [PDF]

				A. V. Mazin, A. A. Alexeev, and S. C. Kowalczykowski A Novel Function of Rad54 Protein. STABILIZATION OF THE Rad51 NUCLEOPROTEIN FILAMENT J. Biol. Chem., April 11, 2003; 278(16): 14029 - 14036. [Abstract] [Full Text] [PDF]

				Y. Aylon, B. Liefshitz, G. Bitan-Banin, and M. Kupiec Molecular Dissection of Mitotic Recombination in the Yeast Saccharomyces cerevisiae Mol. Cell. Biol., February 15, 2003; 23(4): 1403 - 1417. [Abstract] [Full Text] [PDF]

				J. Schmuckli-Maurer, M. Rolfsmeier, H. Nguyen, and W.-D. Heyer Genome instability in rad54 mutants of Saccharomyces cerevisiae Nucleic Acids Res., February 1, 2003; 31(3): 1013 - 1023. [Abstract] [Full Text] [PDF]

				E. N. Asleson and D. M. Livingston Investigation of the Stability of Yeast rad52 Mutant Proteins Uncovers Post-translational and Transcriptional Regulation of Rad52p Genetics, January 1, 2003; 163(1): 91 - 101. [Abstract] [Full Text] [PDF]

				F. Fabre, A. Chan, W.-D. Heyer, and S. Gangloff Alternate pathways involving Sgs1/Top3, Mus81/ Mms4, and Srs2 prevent formation of toxic recombination intermediates from single-stranded gaps created by DNA replication PNAS, December 24, 2002; 99(26): 16887 - 16892. [Abstract] [Full Text] [PDF]

				L. S. Symington Role of RAD52 Epistasis Group Genes in Homologous Recombination and Double-Strand Break Repair Microbiol. Mol. Biol. Rev., December 1, 2002; 66(4): 630 - 670. [Abstract] [Full Text] [PDF]

				K. Kiianitsa, J. A. Solinger, and W.-D. Heyer Rad54 Protein Exerts Diverse Modes of ATPase Activity on Duplex DNA Partially and Fully Covered with Rad51 Protein J. Biol. Chem., November 22, 2002; 277(48): 46205 - 46215. [Abstract] [Full Text] [PDF]

				M. Maftahi, J. C. Hope, L. Delgado-Cruzata, C. S. Han, and G. A. Freyer The severe slow growth of {Delta}srs2{Delta}rqh1 in Schizosaccharomyces pombe is suppressed by loss of recombination and checkpoint genes Nucleic Acids Res., October 15, 2002; 30(21): 4781 - 4792. [Abstract] [Full Text] [PDF]

				E. A. Morgan, N. Shah, and L. S. Symington The Requirement for ATP Hydrolysis by Saccharomyces cerevisiae Rad51 Is Bypassed by Mating-Type Heterozygosity or RAD54 in High Copy Mol. Cell. Biol., September 15, 2002; 22(18): 6336 - 6343. [Abstract] [Full Text] [PDF]

				P. M. Kim, K. S. Paffett, J. A. Solinger, W.-D. Heyer, and J. A. Nickoloff Spontaneous and double-strand break-induced recombination, and gene conversion tract lengths, are differentially affected by overexpression of wild-type or ATPase-defective yeast Rad54 Nucleic Acids Res., July 1, 2002; 30(13): 2727 - 2735. [Abstract] [Full Text] [PDF]

				Y. Huang Transcriptional silencing in Saccharomyces cerevisiae and Schizosaccharomyces pombe Nucleic Acids Res., April 1, 2002; 30(7): 1465 - 1482. [Abstract] [Full Text] [PDF]

				J. A. Solinger and W.-D. Heyer Rad54 protein stimulates the postsynaptic phase of Rad51 protein-mediated DNA strand exchange PNAS, July 17, 2001; 98(15): 8447 - 8453. [Abstract] [Full Text] [PDF]

				L. Krejci, J. Damborsky, B. Thomsen, M. Duno, and C. Bendixen Molecular Dissection of Interactions between Rad51 and Members of the Recombination-Repair Group Mol. Cell. Biol., February 1, 2001; 21(3): 966 - 976. [Abstract] [Full Text]

				H. L. Klein Mutations in Recombinational Repair and in Checkpoint Control Genes Suppress the Lethal Combination of srs2{{Delta}} With Other DNA Repair Genes in Saccharomyces cerevisiae Genetics, February 1, 2001; 157(2): 557 - 565. [Abstract] [Full Text]

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				V. Badarinarayana, Y.-C. Chiang, and C. L. Denis Functional Interaction of CCR4-NOT Proteins With TATAA-Binding Protein (TBP) and Its Associated Factors in Yeast Genetics, July 1, 2000; 155(3): 1045 - 1054. [Abstract] [Full Text]

				D. Guardavaccaro, G. Corrente, F. Covone, L. Micheli, I. D'Agnano, G. Starace, M. Caruso, and F. Tirone Arrest of G1-S Progression by the p53-Inducible Gene PC3 Is Rb Dependent and Relies on the Inhibition of Cyclin D1 Transcription Mol. Cell. Biol., March 1, 2000; 20(5): 1797 - 1815. [Abstract] [Full Text]

				Y. Bai, A. P. Davis, and L. S. Symington A Novel Allele of RAD52 That Causes Severe DNA Repair and Recombination Deficiencies Only in the Absence of RAD51 or RAD59 Genetics, November 1, 1999; 153(3): 1117 - 1130. [Abstract] [Full Text]

				A. Dupressoir, W. Barbot, M.-P. Loireau, and T. Heidmann Characterization of a Mammalian Gene Related to the Yeast CCR4 General Transcription Factor and Revealed by Transposon Insertion J. Biol. Chem., October 22, 1999; 274(43): 31068 - 31075. [Abstract] [Full Text] [PDF]