title: Distribution of acetylated histones resulting from Gal4-VP16 recruitment of SAGA and NuA4 complexes.
abstract: We analyzed the targeting of histone acetyltransferase (HAT) complexes by DNA-binding activators during transcriptional activation and the resulting distribution of acetylated histones. An in vitro competition assay was developed to acetylate and transcribe a nucleosomal array template in the presence of excess non-specific chromatin, which mimics in vivo conditions. Stimulation of transcription from the nucleosomal array template under competitive conditions by the SAGA and NuA4 HAT complexes depended on the presence of the Gal4-VP16 activator, which recognizes sites in the promoter and directly interacts with these HATs. Importantly, the stimulation of transcription by SAGA and NuA4 depended on the presence of Gal4-VP16 during histone acetylation, and Gal4-VP16-bound nucleosomal templates were acetylated preferentially by SAGA and NuA4 relative to the competitor chromatin. While targeting of the SAGA complex led to H3 acetylation of promoter-proximal nucleosomes, targeting of the NuA4 complex led to a broader domain of H4 acetylation of >3 kbp. Thus, either promoter-proximal H3 acetylation by SAGA or broadly distributed acetylation of H4 by NuA4 activated transcription from chromatin templates.
authors.affiliation: Howard Hughes Medical Institute and Department of Biochemistry and Molecular Biology, The Pennsylvania State University, 306 Althouse Laboratory, University Park, PA 16802, USA.
authors.forename: M
authors.initials: M
authors.lastname: Vignali
authors.forename: D J
authors.initials: DJ
authors.lastname: Steger
authors.forename: K E
authors.initials: KE
authors.lastname: Neely
authors.forename: J L
authors.initials: JL
authors.lastname: Workman
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000378:metabolism*; D001667:Binding, Competitive; D002843:Chromatin / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D051548:Histone Acetyltransferases; D006657:Histones / Q000032:analysis / Q000378:metabolism*; D046911:Macromolecular Substances; D009707:Nucleosomes / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D013698:Templates, Genetic; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D002843:Chromatin; D005656:Fungal Proteins; C070633:Gal-VP16; D006657:Histones; D046911:Macromolecular Substances; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D000123:Acetyltransferases; D051548:Histone Acetyltransferases