title: A RSC/nucleosome complex determines chromatin architecture and facilitates activator binding.
abstract: How is chromatin architecture established and what role does it play in transcription? We show that the yeast regulatory locus UASg bears, in addition to binding sites for the activator Gal4, sites bound by the RSC complex. RSC positions a nucleosome, evidently partially unwound, in a structure that facilitates Gal4 binding to its sites. The complex comprises a barrier that imposes characteristic features of chromatin architecture. In the absence of RSC, ordinary nucleosomes encroach over the UASg and compete with Gal4 for binding. Taken with our previous work, the results show that both prior to and following induction, specific DNA-binding proteins are the predominant determinants of chromatin architecture at the GAL1/10 genes. RSC/nucleosome complexes are also found scattered around the yeast genome. Higher eukaryotic RSC lacks the specific DNA-binding determinants found on yeast RSC, and evidently Gal4 works in those organisms despite whatever obstacle broadly positioned nucleosomes present.
authors.affiliation: Molecular Biology Program, Sloan Kettering Institute, 1275 York Avenue, New York, NY 10021, USA.
authors.forename: Monique
authors.initials: M
authors.lastname: Floer
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Vidya
authors.initials: V
authors.lastname: Prabhu
authors.forename: Georgina
authors.initials: G
authors.lastname: Berrozpe
authors.forename: Santosh
authors.initials: S
authors.lastname: Narayan
authors.forename: Dan
authors.initials: D
authors.lastname: Spagna
authors.forename: David
authors.initials: D
authors.lastname: Alvarez
authors.forename: Jude
authors.initials: J
authors.lastname: Kendall
authors.forename: Alexander
authors.initials: A
authors.lastname: Krasnitz
authors.forename: Asya
authors.initials: A
authors.lastname: Stepansky
authors.forename: James
authors.initials: J
authors.lastname: Hicks
authors.forename: Gene O
authors.initials: GO
authors.lastname: Bryant
authors.forename: Mark
authors.initials: M
authors.lastname: Ptashne
mesh_terms: D002843:Chromatin / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005686:Galactokinase / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism*; D050436:Regulatory Elements, Transcriptional; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; C518355:GAL10 protein, S cerevisiae; D009707:Nucleosomes; C103337:RSC complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C524219:GAL1 protein, S cerevisiae; D005686:Galactokinase