title: Human transcription release factor 2 dissociates RNA polymerases I and II stalled at a cyclobutane thymine dimer.
abstract: RNA polymerase II stalled at a lesion in the transcribed strand is thought to constitute a signal for transcription-coupled repair. Transcription factors that act on RNA polymerase in elongation mode potentially influence this mode of repair. Previously, it was shown that transcription elongation factors TFIIS and Cockayne's syndrome complementation group B protein did not disrupt the ternary complex of RNA polymerase II stalled at a thymine cyclobutane dimer, nor did they enable RNA polymerase II to bypass the dimer. Here we investigated the effect of the transcription factor 2 on RNA polymerase II and RNA polymerase I stalled at thymine dimers. Transcription factor 2 is known to release transcripts from RNA polymerase II early elongation complex generated by pulse-transcription. We found that factor 2 (which is also called release factor) disrupts the ternary complex of RNA polymerase II at a thymine dimer and surprisingly exerts the same effect on RNA polymerase I. These findings show that in mammalian cells a RNA polymerase I or RNA polymerase II transcript truncated by a lesion in the template strand may be discarded unless repair is accomplished rapidly by a mechanism that does not displace stalled RNA polymerases.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
authors.forename: R
authors.initials: R
authors.lastname: Hara
authors.forename: C P
authors.initials: CP
authors.lastname: Selby
authors.forename: M
authors.initials: M
authors.lastname: Liu
authors.forename: D H
authors.initials: DH
authors.lastname: Price
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D018983:DNA Footprinting; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics; D045643:DNA Repair Enzymes; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I; D006801:Humans; D009838:Oligodeoxyribonucleotides; D000075223:Poly-ADP-Ribose Binding Proteins; D011740:Pyrimidine Dimers / Q000235:genetics*; D012318:RNA Polymerase I / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics; D013698:Templates, Genetic; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D000075223:Poly-ADP-Ribose Binding Proteins; D011740:Pyrimidine Dimers; D011994:Recombinant Proteins; D014157:Transcription Factors; D012319:RNA Polymerase II; D012318:RNA Polymerase I; D003850:Deoxyribonuclease I; D004265:DNA Helicases; C078673:ERCC6 protein, human; D045643:DNA Repair Enzymes