title: Preferential occupancy of histone variant H2AZ at inactive promoters influences local histone modifications and chromatin remodeling.
abstract: The yeast histone variant H2AZ (Htz1) is implicated in transcription activation, prevention of the ectopic spread of heterochromatin, and genome integrity. Our genome-wide localization analysis revealed that Htz1 is widely, but nonrandomly, distributed throughout the genome in an SWR1-dependent manner. We found that Htz1 is enriched in intergenic regions compared with coding regions. Its occupancy is inversely proportional to transcription rates and the enrichment of the RNA polymerase II under different growth conditions. However, Htz1 does not seem to directly regulate transcription repression genome-wide; instead, the presence of Htz1 under the inactivated condition is essential for optimal activation of a subset of genes. In addition, Htz1 is not generally responsible for nucleosome positioning, even at those promoters where Htz1 is highly enriched. Finally, using a biochemical approach, we demonstrate that incorporation of Htz1 into nucleosomes inhibits activities of histone modifiers associated with transcription, Dot1, Set2, and NuA4 and reduces the nucleosome mobilization driven by chromatin remodeling complexes. These lines of evidence collectively suggest that Htz1 may serve to mark quiescent promoters for proper activation.
authors.affiliation: Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.forename: Samantha G
authors.initials: SG
authors.lastname: Pattenden
authors.forename: Daeyoup
authors.initials: D
authors.lastname: Lee
authors.forename: José
authors.initials: J
authors.lastname: Gutiérrez
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Chris
authors.initials: C
authors.lastname: Seidel
authors.forename: Jennifer
authors.initials: J
authors.lastname: Gerton
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Workman
mesh_terms: D042002:Chromatin Assembly and Disassembly; D020869:Gene Expression Profiling; D016681:Genome, Fungal; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D006657:Histones; C493530:Htz1 protein, S cerevisiae; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins