title: RNA Polymerase-I-Dependent Transcription-coupled Nucleotide Excision Repair of UV-Induced DNA Lesions at Transcription Termination Sites, in Saccharomyces cerevisiae.
abstract: If not repaired, ultraviolet light-induced DNA damage can lead to genome instability. Nucleotide excision repair (NER) of UV photoproducts is generally fast in the coding region of genes, where RNA polymerase-II (RNAP2) arrest at damage sites and trigger transcription-coupled NER (TC-NER). In Saccharomyces cerevisiae, there is RNA polymerase-I (RNAP1)-dependent TC-NER, but this process remains elusive. Therefore, we wished to characterize TC-NER efficiency in different regions of the rDNA locus: where RNAP1 are present at high density and start transcription elongation, where the elongation rate is slow, and in the transcription terminator where RNAP1 pause, accumulate and then are released. The Rpa12 subunit of RNAP1 and the Nsi1 protein participate in transcription termination, and NER efficiency was compared between wild type and cells lacking Rpa12 or Nsi1. The presence of RNAP1 was determined by chromatin endogenous cleavage and chromatin immunoprecipitation, and repair was followed at nucleotide precision with an assay that is based on the blockage of Taq polymerase by UV photoproducts. We describe that TC-NER, which is modulated by the RNAP1 level and elongation rate, ends at the 35S rRNA gene transcription termination site.
authors.affiliation: Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Peyresaubes
authors.affiliation: Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Carlos
authors.initials: C
authors.lastname: Zeledon
authors.affiliation: Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Guintini
authors.affiliation: Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Romain
authors.initials: R
authors.lastname: Charton
authors.affiliation: Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Alexia
authors.initials: A
authors.lastname: Muguet
authors.affiliation: Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Antonio
authors.initials: A
authors.lastname: Conconi
mesh_terms: D002843:Chromatin / Q000235:genetics; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004271:DNA, Fungal / Q000528:radiation effects*; D012318:RNA Polymerase I / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D061806:Transcription Termination, Genetic; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
chemical_list: D002843:Chromatin; D004271:DNA, Fungal; D012335:RNA, Ribosomal; D004247:DNA; D012318:RNA Polymerase I