Yeast Sen1 helicase protects the genome from transcription-associated instability.

Journal article

Sen1 of S. cerevisiae is a known component of the NRD complex implicated in transcription termination of nonpolyadenylated as well as some polyadenylated RNA polymerase II transcripts. We now show that Sen1 helicase possesses a wider function by restricting the occurrence of RNA:DNA hybrids that may naturally form during transcription, when nascent RNA hybridizes to DNA prior to its packaging into RNA protein complexes. These hybrids displace the nontranscribed strand and create R loop structures. Loss of Sen1 results in transient R loop accumulation and so elicits transcription-associated recombination. SEN1 genetically interacts with DNA repair genes, suggesting that R loop resolution requires proteins involved in homologous recombination. Based on these findings, we propose that R loop formation is a frequent event during transcription and a key function of Sen1 is to prevent their accumulation and associated genome instability.

Authors: Mischo, H; Gómez-González, B; Grzechnik, P; Rondón, A; Wei, W

• Publication status: Published
• Journal: Molecular cell
• Volume: 41
• Issue: 1
• Pages: 21-32
• Publication date: 2011-01-01
• DOI: 10.1016/j.molcel.2010.12.007
• EISSN: 1097-4164
• ISSN: 1097-2765
• Language: English
• Keywords: Saccharomyces cerevisiae; Recombination, Genetic; Nucleic Acid Conformation; Genomic Instability; Protein Structure, Tertiary; DNA Repair; Saccharomyces cerevisiae Proteins; RNA Helicases; Transcription, Genetic; DNA Damage; Nucleic Acid Hybridization; DNA Helicases