title: Three yeast proteins related to the human candidate tumor suppressor p33(ING1) are associated with histone acetyltransferase activities.
abstract: Three Saccharomyces cerevisiae proteins (Yng1/YOR064c, Yng2/YHR090c, and Pho23) and two Schizosaccharomyces pombe proteins (Png1/CAA15917 and Png2/CAA21250) share significant sequence identity with the human candidate tumor suppressor p33(ING1) in their C-terminal regions. The homologous regions contain PHD finger domains which have been implicated in chromatin-mediated transcriptional regulation. We show that GFP-Yng2, like human Ing1, is localized in the nucleus. Deletion of YNG2 results in several phenotypes, including an abnormal multibudded morphology, an inability to utilize nonfermentable carbon sources, heat shock sensitivity, slow growth, temperature sensitivity, and sensitivity to caffeine. These phenotypes are suppressed by expression of either human Ing1 or S. pombe Png1, suggesting that the yeast and human proteins are functionally conserved. Yng1- and Pho23-deficient cells also share some of these phenotypes. We demonstrated by yeast two-hybrid and coimmunoprecipitation tests that Yng2 interacts with Tra1, a component of histone acetyltransferase (HAT) complexes. We further demonstrated by coimmunoprecipitation that HA-Yng1, HA-Yng2, HA-Pho23, and HA-Ing1 are associated with HAT activities in yeast. Genetic and biochemical evidence indicate that the Yng2-associated HAT is Esa1, suggesting that Yng2 is a component of the NuA4 HAT complex. These studies suggest that the yeast Ing1-related proteins are involved in chromatin remodeling. They further suggest that these functions may be conserved in mammals and provide a possible mechanism for the human Ing1 candidate tumor suppressor.
authors.affiliation: Departments of Biochemistry and Molecular Biology and Oncology, University of Calgary Health Sciences Centre, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Loewith
authors.forename: M
authors.initials: M
authors.lastname: Meijer
authors.forename: S P
authors.initials: SP
authors.lastname: Lees-Miller
authors.forename: K
authors.initials: K
authors.lastname: Riabowol
authors.forename: D
authors.initials: D
authors.lastname: Young
mesh_terms: D000123:Acetyltransferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D005816:Genetic Complementation Test; D051548:Histone Acetyltransferases; D006801:Humans; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins; D010641:Phenotype; D049294:Phospholipid Transfer Proteins; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000201:enzymology* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D025521:Tumor Suppressor Proteins
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C501503:ING1 protein, human; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D049294:Phospholipid Transfer Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; C491364:TRA1 protein, S cerevisiae; D025521:Tumor Suppressor Proteins; D000123:Acetyltransferases; C496551:Esa1 protein, S cerevisiae; D051548:Histone Acetyltransferases