Saccharomyces cerevisiae DNA recombination and repair functions of the RAD52 epistasis group inhibit Ty1 transposition

• Published in: Genetics (Austin) Vol. 154; no. 2; pp. 543 - 556
• Main Authors: Rattray, A.J, Shafer, B.K, Garfinkel, D.J
• Format: Journal Article
• Language: English
• Published: United States Genetics Soc America 01.02.2000; Genetics Society of America
• Subjects: CDC9 gene; complementary DNA; Deoxyribonucleic acid; DNA; dna ligase; DNA ligase I; DNA Ligases - metabolism; DNA Repair; DNA, Complementary; DNA, Fungal - genetics; DNA-Binding Proteins - genetics; Epistasis, Genetic; gene expression; Gene Expression Regulation, Fungal; genes; Genes, Fungal; Genomics; homologous recombination; inhibition; ligases; messenger RNA; MSH2 gene; mutants; mutation; RAD1 gene; RAD2 gene; RAD50 gene; RAD51 gene; Rad52 DNA Repair and Recombination Protein; RAD52 gene; RAD54 gene; RAD57 gene; Recombination, Genetic; Retroelements; retrotransposons; Ribonucleic acid; RNA; RNA, Messenger - genetics; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins; transcription (genetics); transposition; transposon Ty1
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/154.2.543

RNA transcribed from the Saccharomyces cerevisiae retrotransposon Ty1 accumulates to a high level in mitotically growing haploid cells, yet transposition occurs at very low frequencies. The product of reverse transcription is a linear double-stranded DNA molecule that reenters the genome by either Ty1-integrase-mediated insertion or homologous recombination with one of the preexisting genomic Ty1 (or delta) elements. Here we examine the role of the cellular homologous recombination functions on Ty1 transposition. We find that transposition is elevated in cells mutated for genes in the RAD52 recombinational repair pathway, such as RAD50, RAD51, RAD52, RAD54, or RAD57, or in the DNA ligase I gene CDC9, but is not elevated in cells mutated in the DNA repair functions encoded by the RAD1, RAD2, or MSH2 genes. The increase in Ty1 transposition observed when genes in the RAD52 recombinational pathway are mutated is not associated with a significant increase in Ty1 RNA or proteins. However, unincorporated Ty1 cDNA levels are markedly elevated. These results suggest that members of the RAD52 recombinational repair pathway inhibit Ty1 post-translationally by influencing the fate of Ty1 cDNA.