title: Acetylation and accessibility of rDNA chromatin in Saccharomyces cerevisiae in (Delta)top1 and (Delta)sir2 mutants.
abstract: The insertion of reporter genes in the ribosomal DNA (rDNA) locus of Saccharomyces cerevisiae causes their transcriptional repression. This kind of transcriptional silencing depends on proteins such as Sir2p and Top1p, and has been shown to be mediated by chromatin. While Sir2p modifies nucleosomes directly through its histone deacetylase activity, little is known about changes in the chromatin structure that occur at the rDNA locus when TOP1 is deleted. Here, we show that the absence of Top1p causes increased histone acetylation at the rDNA locus. Moreover, rDNA chromatin becomes more accessible in a similar manner in both top1 and sir2 mutant strains.
authors.affiliation: Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, P. le A. Moro 5, 00185 Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cioci
authors.forename: Maria
authors.initials: M
authors.lastname: Vogelauer
authors.forename: Giorgio
authors.initials: G
authors.lastname: Camilloni
mesh_terms: D000107:Acetylation; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004264:DNA Topoisomerases, Type I / Q000235:genetics / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing; D005800:Genes, Fungal / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D008836:Micrococcal Nuclease / Q000378:metabolism; D005810:Multigene Family / Q000235:genetics; D009154:Mutation; D009707:Nucleosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011233:Precipitin Tests; D012270:Ribosomes / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins
chemical_list: D002843:Chromatin; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D006657:Histones; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D015534:Trans-Activators; D014764:Viral Proteins; D005090:Exodeoxyribonucleases; C043586:exo protein, Bacteriophage lambda; D015252:Deoxyribonucleases, Type II Site-Specific; C027440:GATATC-specific type II deoxyribonucleases; D008836:Micrococcal Nuclease; C087778:SIR2 protein, S cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D006655:Histone Deacetylases; D004264:DNA Topoisomerases, Type I