A postincision-deficient TFIIH causes replication fork breakage and uncovers alternative Rad51- or Pol32-mediated restart mechanisms.
Homologous recombination is a major double-strand break (DSB) repair mechanism that acts during the S and G2 phases. In contrast, nucleotide excision repair (NER) is a major pathway for the repair of DNA bulky adducts that is unrelated to replication. We show that replication can be strongly disturbed in a specific type of rad3/XPD NER mutant of TFIIH, causing replication fork breakage. In contrast to classical NER-deficient mutations, the S. cerevisiae rad3-102 allele, which has a minimal impact on UV resistance, channels bulky adducts into DSBs. rad3-102 allows Rad1/XPF- and Rad2/XPG-catalyzed DNA incisions but fails to perform postincision steps retaining TFIIH at the damaged site. Broken forks are rescued by MRX-Rad52-Rfc1-dependent recombination via two types of replication restart mechanisms, one being Rad51 dependent and the other Pol32 dependent. Our results define the genetic and molecular hallmarks of replication fork breakage and restart and bring insights to understand specific NER-related human syndromes.
Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC, Av. Américo Vespucio s/n, 41092 Sevilla, Spain.
María
M
Moriel-Carretero
Andrés
A
Aguilera
D053903:DNA Breaks, Double-Stranded; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair / Q000528:radiation effects; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication / Q000528:radiation effects; D004271:DNA, Fungal / Q000096:biosynthesis* / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D004307:Dose-Response Relationship, Radiation; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism; D042822:Genomic Instability; D005838:Genotype; D006801:Humans; D009154:Mutation; D010641:Phenotype; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*; D051721:Rad52 DNA Repair and Recombination Protein / Q000235:genetics / Q000378:metabolism; D011836:Radiation Tolerance; D011995:Recombination, Genetic / Q000528:radiation effects; D051818:Replication Protein C / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D051758:Transcription Factor TFIIH / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C522758:Pol32 protein, S cerevisiae; C497197:RAD52 protein, S cerevisiae; C084903:RFC1 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; C073998:RAD2 protein, S cerevisiae; D051758:Transcription Factor TFIIH; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D004259:DNA-Directed DNA Polymerase; D004706:Endodeoxyribonucleases; D004720:Endonucleases; C069266:RAD1 protein, S cerevisiae; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases; D051818:Replication Protein C; D045643:DNA Repair Enzymes