Stimulation of mitotic recombination upon transcription from the yeast GAL1 promoter but not from other RNA polymerase I, II and III promoters.
Homologous recombination in Saccharomyces cerevisiae and other organisms can be stimulated by transcription. Consistent with this, we find that recombination of a chromosomal ade1 allele with a plasmid-borne ADE1 ORF under the control of the GAL1 promoter increased from 6.1x10(-6) to 1.7x10(-4) when transcription of the plasmid locus was induced by growing the cells in the presence of galactose. Recombination could also be stimulated by over-expressing the Gal4 transcription factor in the presence of the GAL1-ADE1 plasmid, while culturing the cells in dextrose medium. However, when transcription of the same ORF was driven from the highly active promoters of the rDNA (RNA polymerase I), and ADH1 (RNA polymerase II) genes, only background levels of recombination (5-10x10(-6)) were observed, irrespective of the carbon source. Recombination was found to involve integration of the whole plasmid and to depend on RAD51, RAD52 and RAD54. The results indicate that increased accessibility of transcriptionally active chromatin is not sufficient to cause increased rates of this kind of reciprocal exchange.
Bratty
J
J
Département de biochimie, Université de Montréal, Montréal, H3C 3J7, Canada.
Ferbeyre
G
G
Molinaro
C
C
Cedergren
R
R
D000483:Alleles; D015152:Blotting, Northern; D015139:Blotting, Southern; D002874:Chromosome Mapping; D004265:DNA Helicases; D045643:DNA Repair Enzymes; D004274:DNA, Recombinant / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D005690:Galactose / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D008957:Models, Genetic; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012318:RNA Polymerase I / Q000235:genetics; D012319:RNA Polymerase II / Q000235:genetics; D012320:RNA Polymerase III / Q000235:genetics; D051135:Rad51 Recombinase; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic
D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C495151:RAD51 protein, S cerevisiae; D012319:RNA Polymerase II; D051135:Rad51 Recombinase; D012318:RNA Polymerase I; D012320:RNA Polymerase III; C075468:RAD54 protein, S cerevisiae; D004265:DNA Helicases; D045643:DNA Repair Enzymes; D005690:Galactose