Modulation of Rad26- and Rpb9-mediated DNA repair by different promoter elements.
Rad26, the yeast homologue of human Cockayne syndrome group B protein, and Rpb9, a nonessential subunit of RNA polymerase II, have been shown to mediate two subpathways of transcription-coupled DNA repair in yeast. Here we show that Rad26- and Rpb9-mediated repair in the yeast GAL1 gene is differently modulated by different promoter elements. The initiation site and efficiency of Rad26-mediated repair in the transcribed strand are determined by the upstream activating sequence (UAS) but not by the TATA or local sequences. The role of UAS in determining the Rad26-mediated repair is not through loading of RNA polymerase II or the transcriptional regulatory complex SAGA. However, both the UAS and the TATA sequences are essential for confining Rad26-mediated repair to the transcribed strand. Mutation of the TATA sequence, which greatly reduces transcription, or deletion of the TATA or mutation of the UAS, which completely abolishes transcription, causes Rad26-mediated repair to occur in both strands. Rpb9-mediated repair only occurs in the transcribed strand and is efficient only in the presence of both TATA and UAS sequences. Also, the efficiency of Rpb9-mediated repair is dependent on the SAGA complex. Our results suggest that Rad26-mediated repair can be either transcription-coupled, provided that a substantial level of transcription is present, or transcription-independent, if the transcription is too low or absent. In contrast, Rpb9-mediated repair is strictly transcription-coupled and is efficient only when the transcription level is high.
Li
Shisheng
S
Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803, USA. shli@lsu.edu
Chen
Xuefeng
X
Ruggiero
Christine
C
Ding
Baojin
B
Smerdon
Michael J
MJ
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000502:physiology*; D001483:Base Sequence; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers / Q000737:chemistry; D004260:DNA Repair; D017353:Gene Deletion; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000235:genetics* / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000502:physiology*; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
D017931:DNA Primers; D029701:Saccharomyces cerevisiae Proteins; D012319:RNA Polymerase II; C509257:Rpb9 protein, S cerevisiae; D000251:Adenosine Triphosphatases; C465758:RAD26 protein, S cerevisiae