title: Sen1, the yeast homolog of human senataxin, plays a more direct role than Rad26 in transcription coupled DNA repair.
abstract: Rad26, a DNA dependent ATPase that is homologous to human CSB, has been well known to play an important role in transcription coupled DNA repair (TCR) in the yeast Saccharomyces cerevisiae Sen1, a DNA/RNA helicase that is essential for yeast cell viability and homologous to human senataxin, has been known to be required for transcriptional termination of short noncoding RNA genes and for a fail-safe transcriptional termination mechanism of protein-coding genes. Sen1 has also been shown to protect the yeast genome from transcription-associated recombination by resolving RNA:DNA hybrids naturally formed during transcription. Here, we show that the N-terminal non-essential region of Sen1 plays an important role in TCR, whereas the C-terminal nonessential region and the helicase activity of Sen1 are largely dispensable for the repair. Unlike Rad26, which becomes completely dispensable for TCR in cells lacking the TCR repressor Spt4, Sen1 is still required for efficient TCR in the absence of Spt4. Also unlike Rad26, which is important for repair at many but not all damaged sites in the transcribed strand of a gene, Sen1 is required for efficient repair at essentially all the damaged sites. Our results indicate that Sen1 plays a more direct role than Rad26 in TCR.
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Wentao
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Kathiresan
authors.initials: K
authors.lastname: Selvam
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Sheikh A
authors.initials: SA
authors.lastname: Rahman
authors.affiliation: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA shli@lsu.edu.
authors.forename: Shisheng
authors.initials: S
authors.lastname: Li
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D015139:Blotting, Southern; D004265:DNA Helicases / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair / Q000235:genetics* / Q000528:radiation effects; D004843:Epistasis, Genetic / Q000528:radiation effects; D017353:Gene Deletion; D016681:Genome, Fungal; D006801:Humans; D064251:Multifunctional Enzymes; D009687:Nuclear Proteins / Q000378:metabolism; D017354:Point Mutation / Q000235:genetics; D000072417:Protein Domains; D011740:Pyrimidine Dimers / Q000378:metabolism; D020365:RNA Helicases / Q000737:chemistry* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D013997:Time Factors; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000378:metabolism
chemical_list: D064251:Multifunctional Enzymes; D009687:Nuclear Proteins; D011740:Pyrimidine Dimers; C080991:SPT4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035602:Transcriptional Elongation Factors; D000251:Adenosine Triphosphatases; C542347:SEN1 protein, S cerevisiae; C484368:SETX protein, human; C465758:RAD26 protein, S cerevisiae; D004265:DNA Helicases; D020365:RNA Helicases