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  • The EMBO Journal (2007) 26, 2868 - 2879
  • doi:10.1038/sj.emboj.7601728

Published online: 17 May 2007

A genome-wide role for CHD remodelling factors and Nap1 in nucleosome disassembly

Julian Walfridsson1, Olga Khorosjutina2, Paulina Matikainen2, Claes M Gustafsson2 and Karl Ekwall1

  1. Karolinska Institutet, Department of Biosciences and Medical Nutrition/School of Life Sciences, University College Sodertorn, Huddinge, Sweden
  2. Division of Metabolic Disorders, Department of Laboratory Medicine, Karolinska Institutet, Novum, Huddinge Sweden

Correspondence to:

Julian WalfridssonKarl Ekwall, School of Life Sciences, University College Sodertorn, Alfred Nobel's Allé 7, 141 89 Huddinge, Sweden. Tel.: +46 8 608 4713; Fax: +46 8 608 4510; E-mail: karl.ekwall@sh.se or Tel.: +46 8 608 4713; +46 8 608 4709; E-mail: julian.walfridsson@sh.se

Received 18 December 2006; Accepted 26 April 2007

Chromatin remodelling factors and histone chaperones were previously shown to cooperatively affect nucleosome assembly and disassembly processes in vitro. Here, we show that Schizosaccharomyces pombe CHD remodellers, the Hrp1 and Hrp3 paralogs physically interact with the histone chaperone Nap1. Genome-wide analysis of Hrp1, Hrp3 and Nap1 occupancy, combined with nucleosome density measurements revealed that the CHD factors and Nap1 colocalized in particular to promoter regions where they remove nucleosomes near the transcriptional start site. Hrp1 and Hrp3 also regulate nucleosome density in coding regions, where they have redundant roles to stimulate transcription. Previously, DNA replication-dependent and -independent nucleosome disassembly processes have been described. We found that nucleosome density increased in the hrp1 mutant in the absence of DNA replication. Finally, regions where nucleosome density increased in hrp1, hrp3 and nap1 mutants also showed nucleosome density and histone modification changes in HDAC and HAT mutants. Thus, this study revealed an important in vivo role for CHD remodellers and Nap1 in nucleosome disassembly at promoters and coding regions, which are linked to changes in histone acetylation.

  • Keywords:

    • CHD,
    • chromatin,
    • fission yeast,
    • gene regulation,
    • nucleosome remodelling