1. Topoisomerase I regulates open chromatin and controls gene expression in vivo
- Author
-
Edgar Hartsuiker, Ulrika Norman, Mickaël Durand-Dubief, Jenna Persson, and Karl Ekwall
- Subjects
Histone-modifying enzymes ,Transcription, Genetic ,Nucleosome disassembly ,Biology ,Article ,General Biochemistry, Genetics and Molecular Biology ,Histones ,Gene Expression Regulation, Fungal ,Schizosaccharomyces ,Nucleosome ,Histone code ,Promoter Regions, Genetic ,Molecular Biology ,General Immunology and Microbiology ,General Neuroscience ,DNA Helicases ,ChIP-on-chip ,Molecular biology ,Chromatin ,Nucleosomes ,Cell biology ,DNA Topoisomerases, Type II ,Histone ,DNA Topoisomerases, Type I ,biology.protein ,DNA supercoil ,RNA Polymerase II ,Schizosaccharomyces pombe Proteins - Abstract
DNA topoisomerases regulate the topological state of the DNA double helix and are key enzymes in the processes of DNA replication, transcription and genome stability. Using the fission yeast model Schizosaccharomyces pombe, we investigate genome wide how DNA topoisomerases I and II affect chromatin dynamics and gene expression in vivo. We show that topoisomerase I activity is directly required for efficient nucleosome disassembly at gene promoter regions. Lack of topoisomerase activity results in increased nucleosome occupancy, perturbed histone modifications and reduced transcription from these promoters. Strong correlative evidence suggests that topoisomerase I cooperates with the ATP-dependent chromatin remodeller Hrp1 in nucleosome disassembly. Our study links topoisomerase activity to the maintenance of open chromatin and regulating transcription in vivo.
- Published
- 2010