Mutations in the yeast SRB2 general transcription factor suppress hpr1-induced recombination and show defects in DNA repair.
We have obtained genetic and molecular evidence that the hrs2-1 mutation, isolated as a suppressor of the hyperrecombination phenotype of hpr1 delta, is in the SRB2 gene, which encodes a component of the RNA polII holoenzyme. A newly constructed srb2 delta allele restores the wild-type levels of deletions in hpr1 delta cells, indicating that the lack of a functional SRB2 transcription factor suppresses recombination between direct repeats. These results suggest a direct connection between transcription and recombination between DNA repeats. On the other hand, the hrs2-1 mutation (renamed srb2-101), in which Gly150 has been changed to Asp, makes cells sensitive to long MMS treatments, a phenotype observed for the srb2 delta null allele only in a hpr1 delta background. This indicates that mutations in the basal transcription factor SRB2 impair DNA repair of MMS-induced damage, which adds a new connection between transcription and DNA repair. We discuss the possibility that hpr1-induced deletions occurred as a consequence of a SRB2-dependent stalled or blocked transcription complex.
Piruat
J I
JI
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Spain.
Aguilera
A
A
D000483:Alleles; D004260:DNA Repair / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal; D056892:Mediator Complex; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D009153:Mutagens / Q000494:pharmacology; D009154:Mutation; D009687:Nuclear Proteins; D010641:Phenotype; D017354:Point Mutation; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D005656:Fungal Proteins; C063494:HPR1 protein, S cerevisiae; D056892:Mediator Complex; D009153:Mutagens; D009687:Nuclear Proteins; C074748:SRB2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D008741:Methyl Methanesulfonate