Defective nucleotide excision repair in yeast hpr1 and tho2 mutants.
Nucleotide excision repair (NER) and transcription are intimately related. First, TFIIH has a dual role in transcription initiation and NER and, secondly, transcription leads to more efficient repair of damage present in transcribed sequences. It is thought that elongating RNAPII, stalled at a DNA lesion, is used for the loading of the NER machinery in a process termed transcription-coupled repair (TCR). Non-transcribed regions are repaired by the so-called global genome repair (GGR). We have previously defined a number of yeast genes, whose deletions confer transcription-dependent hyper-recombination phenotypes. As these mutations cause impairment of transcription elongation we have assayed whether they also affect DNA repair. We show that null mutations of the HPR1 and THO2 genes, encoding two prominent proteins of the THO complex, increase UV sensitivity of yeast cells lacking GGR. Consistent with this result, molecular analyses of DNA repair of the RPB2 transcribed strand using T4 endo V show that hpr1 and tho2 do indeed impair TCR. However, this effect is not confined to TCR alone because the mutants are slightly affected in GGR. These results indicate that THO affects both transcription and NER. We discuss different alternatives to explain the effect of the THO complex on DNA repair.
González-Barrera
Sergio
S
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes 6, 41012 Sevilla, Spain.
Prado
Félix
F
Verhage
Richard
R
Brouwer
Jaap
J
Aguilera
Andrés
A
D015152:Blotting, Northern; D018797:Cell Cycle Proteins; D004260:DNA Repair / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D004268:DNA-Binding Proteins; D043224:Deoxyribonuclease (Pyrimidine Dimer); D004307:Dose-Response Relationship, Radiation; D004706:Endodeoxyribonucleases / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000528:radiation effects; D005838:Genotype; D000072235:Mating Factor; D009154:Mutation; D009687:Nuclear Proteins; D010455:Peptides / Q000235:genetics; D021122:Protein Subunits; D012319:RNA Polymerase II / Q000235:genetics; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase / Q000235:genetics; D014466:Ultraviolet Rays
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C063494:HPR1 protein, S cerevisiae; D009687:Nuclear Proteins; D010455:Peptides; D021122:Protein Subunits; C063915:RAD7 protein, S cerevisiae; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C405934:THO2 protein, S cerevisiae; D014157:Transcription Factors; C088086:rad26 protein, S pombe; D000072235:Mating Factor; D012319:RNA Polymerase II; D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase; D004706:Endodeoxyribonucleases; D043224:Deoxyribonuclease (Pyrimidine Dimer)