Abstract
Sir2 and Hst1 are NAD+-dependent deacetylases involved in transcriptional repression in yeast. The two enzymes are highly homologous yet have different sensitivity to the small-molecule inhibitor splitomicin (compound 1) (Bedalov, A., Gatbonton, T., Irvine, W. P., Gottschling, D. E., and Simon, J. A. (2001) Proc. Natl. Acad. Sci. U. S. A. 98, 15113-15118). We have now defined a critical amino acid residue within a small helical module of Hst1 that confers relative resistance to splitomicin. Parallel cell-based screens of 100 splitomicin analogues led to the identification of compounds that exhibit a higher degree of selectivity toward Sir2 or Hst1. A series of compounds based on a splitomicin derivative, dehydrosplitomicin (compound 2), effectively phenocopied a yeast strain that lacked Hst1 deacetylase while having no effect on the silencing activities of Sir2. In addition, we identified a compound with improved selectivity for Sir2. Selectivity was affirmed using whole-genome DNA microarray analysis. This study underscores the power of phenotypic screens in the development and characterization of selective inhibitors of enzyme functions.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Blotting, Northern
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Dose-Response Relationship, Drug
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Drug Resistance, Fungal
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Enzyme Inhibitors / pharmacology*
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Genes, Fungal
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Genes, Reporter
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Genome, Fungal
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Histone Deacetylase Inhibitors*
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Histone Deacetylases / chemistry
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Models, Chemical
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Models, Molecular
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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NAD / metabolism
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Naphthalenes / pharmacology
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Oligonucleotide Array Sequence Analysis
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Phenotype
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Plasmids / metabolism
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Pyrones / pharmacology
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Saccharomyces cerevisiae Proteins / antagonists & inhibitors*
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Saccharomyces cerevisiae Proteins / chemistry
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Sequence Homology, Amino Acid
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Silent Information Regulator Proteins, Saccharomyces cerevisiae / antagonists & inhibitors*
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Silent Information Regulator Proteins, Saccharomyces cerevisiae / chemistry
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Sirtuin 2
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Sirtuins / antagonists & inhibitors*
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Sirtuins / chemistry
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Telomere / ultrastructure
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beta-Galactosidase / metabolism
Substances
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Enzyme Inhibitors
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Histone Deacetylase Inhibitors
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Naphthalenes
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Pyrones
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Saccharomyces cerevisiae Proteins
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Silent Information Regulator Proteins, Saccharomyces cerevisiae
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NAD
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splitomicin
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beta-Galactosidase
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HST1 protein, S cerevisiae
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SIR2 protein, S cerevisiae
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Sirtuin 2
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Sirtuins
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Histone Deacetylases