title: Long-range communication between the silencers of HMR.
abstract: Gene regulation involves long-range communication between silencers, enhancers, and promoters. In Saccharomyces cerevisiae, silencers flank transcriptionally repressed genes to mediate regional silencing. Silencers recruit the Sir proteins, which then spread along chromatin to encompass the entire silenced domain. In this report we have employed a boundary trap assay, an enhancer activity assay, chromatin immunoprecipitations, and chromosome conformation capture analyses to demonstrate that the two HMR silencer elements are in close proximity and functionally communicate with one another in vivo. We further show that silencing is necessary for these long-range interactions, and we present models for Sir-mediated silencing based upon these results.
authors.affiliation: Department of MCD Biology, Sinsheimer Labs, 1156 High Street, University of California, Santa Cruz, California 95064, USA.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Valenzuela
authors.forename: Namrita
authors.initials: N
authors.lastname: Dhillon
authors.forename: Rudra N
authors.initials: RN
authors.lastname: Dubey
authors.forename: Marc R
authors.initials: MR
authors.lastname: Gartenberg
authors.forename: Rohinton T
authors.initials: RT
authors.lastname: Kamakaka
mesh_terms: D047369:Chromatin Immunoprecipitation; D015825:Chromosomes, Fungal / Q000235:genetics* / Q000648:ultrastructure; D004271:DNA, Fungal / Q000235:genetics* / Q000648:ultrastructure; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing / Q000502:physiology*; D049770:Genes, Mating Type, Fungal / Q000235:genetics*; D019901:Locus Control Region / Q000235:genetics*; D008957:Models, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology; D000089804:Shelterin Complex; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae / Q000502:physiology*; D034501:Telomere-Binding Proteins / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology
chemical_list: D004271:DNA, Fungal; C440829:RAP1 protein, S cerevisiae; C084122:SIR3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000089804:Shelterin Complex; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D034501:Telomere-Binding Proteins; D014157:Transcription Factors