title: Identification of a small molecule inhibitor of Sir2p.
abstract: Sir2p is an NAD(+)-dependent histone deacetylase required for chromatin-dependent silencing in yeast. In a cell-based screen for inhibitors of Sir2p, we identified a compound, splitomicin, that creates a conditional phenocopy of a sir2 deletion mutant in Saccharomyces cerevisiae. Cells grown in the presence of the drug have silencing defects at telomeres, silent mating-type loci, and the ribosomal DNA. In addition, whole genome microarray experiments show that splitomicin selectively inhibits Sir2p. In vitro, splitomicin inhibits NAD(+)-dependent histone deacetylase activity (HDA) of the Sir2 protein. Mutations in SIR2 that confer resistance to the drug map to the likely acetylated histone tail binding domain of the protein. By using splitomicin as a chemical genetic probe, we demonstrate that continuous HDA of Sir2p is required for maintaining a silenced state in nondividing cells.
authors.affiliation: Divisions of Clinical Research, Basic Sciences, and Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bedalov
authors.forename: T
authors.initials: T
authors.lastname: Gatbonton
authors.forename: W P
authors.initials: WP
authors.lastname: Irvine
authors.forename: D E
authors.initials: DE
authors.lastname: Gottschling
authors.forename: J A
authors.initials: JA
authors.lastname: Simon
mesh_terms: D000595:Amino Acid Sequence; D004275:DNA, Ribosomal / Q000235:genetics; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009243:NAD / Q000378:metabolism; D009281:Naphthalenes / Q000494:pharmacology*; D020411:Oligonucleotide Array Sequence Analysis; D011753:Pyrones / Q000494:pharmacology*; D011995:Recombination, Genetic / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D004275:DNA, Ribosomal; D056572:Histone Deacetylase Inhibitors; D009281:Naphthalenes; D011753:Pyrones; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D015534:Trans-Activators; D009243:NAD; C444426:splitomicin; C087778:SIR2 protein, S cerevisiae; D056565:Sirtuin 2; D037761:Sirtuins; D006655:Histone Deacetylases