title: The impact of the HIRA histone chaperone upon global nucleosome architecture.
abstract: HIRA is an evolutionarily conserved histone chaperone that mediates replication-independent nucleosome assembly and is important for a variety of processes such as cell cycle progression, development, and senescence. Here we have used a chromatin sequencing approach to determine the genome-wide contribution of HIRA to nucleosome organization in Schizosaccharomyces pombe. Cells lacking HIRA experience a global reduction in nucleosome occupancy at gene sequences, consistent with the proposed role for HIRA in chromatin reassembly behind elongating RNA polymerase II. In addition, we find that at its target promoters, HIRA commonly maintains the full occupancy of the -1 nucleosome. HIRA does not affect global chromatin structure at replication origins or in rDNA repeats but is required for nucleosome occupancy in silent regions of the genome. Nucleosome organization associated with the heterochromatic (dg-dh) repeats located at the centromere is perturbed by loss of HIRA function and furthermore HIRA is required for normal nucleosome occupancy at Tf2 LTR retrotransposons. Overall, our data indicate that HIRA plays an important role in maintaining nucleosome architecture at both euchromatic and heterochromatic loci.
authors.affiliation: a Institute for Cell & Molecular Biosciences ; Newcastle University ; Newcastle upon Tyne , UK.
authors.forename: Csenge
authors.initials: C
authors.lastname: Gal
authors.forename: Karen M
authors.initials: KM
authors.lastname: Moore
authors.forename: Konrad
authors.initials: K
authors.lastname: Paszkiewicz
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Kent
authors.forename: Simon K
authors.initials: SK
authors.lastname: Whitehall
mesh_terms: D002843:Chromatin / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly; D006657:Histones / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C543473:hip1 protein, S pombe; D012319:RNA Polymerase II
keywords: Chromatin; HIRA; S. pombe; heterochromatin; histone chaperone; nucleosome assembly