title: Rad26, the transcription-coupled repair factor in yeast, is required for removal of stalled RNA polymerase-II following UV irradiation.
abstract: Transcription coupled nucleotide excision repair (TCR) is a major pathway responsible for removal of helix distorting DNA lesions from transcriptionally active regions of the genome. Rad26, a key factor of the TCR pathway, is known to play a role during early steps of TCR. Here, we show that Rad26-mediated TCR is not absolutely dependent on active transcription elongation in budding yeast. As per our results, RAD26-deleted cells show enhanced UV sensitivity compared to wild type cells under conditions where transcription elongation is inhibited. The increased UV sensitivity observed in RAD26-deleted cells, however, is not due to reduced expression of the major NER-responsive genes. Interestingly, transcription of the constitutively expressed RPB2 gene is adversely affected in RAD26-deleted cells during UV-induced DNA damage repair. In consonance, chromatin immunoprecipitation analysis showed that unlike in wild type, in RAD26-deleted cells no significant reduction in RNA polymerase II occupancy occurs during nucleotide excision repair in the transcriptionally active loci like, RPB2, PYK1 and RPL2B. These results collectively indicate that removal of RNAPII during DNA damage repair following UV irradiation is dependent on Rad26.
authors.affiliation: Department of Biotechnology, St. Xavier's College, Mother Teresa Sarani, Kolkata, India.
authors.forename: Sounak
authors.initials: S
authors.lastname: Ghosh-Roy
authors.forename: Dhiman
authors.initials: D
authors.lastname: Das
authors.forename: Debarati
authors.initials: D
authors.lastname: Chowdhury
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Smerdon
authors.forename: Michael
authors.initials: M
authors.lastname: J Smerdon
authors.forename: Ronita Nag
authors.initials: RN
authors.lastname: Chaudhuri
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics; D009154:Mutation; D009173:Mycophenolic Acid / Q000494:pharmacology; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays; D014498:Uracil / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D021122:Protein Subunits; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C093571:ribosomal protein YL6, S cerevisiae; D014498:Uracil; D012319:RNA Polymerase II; C511736:RPB1 protein, S cerevisiae; C580821:RPB2 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C465758:RAD26 protein, S cerevisiae; D009173:Mycophenolic Acid; C100248:azauracil