title: Genetic evidence that Ras-like GTPases, Gtr1p, and Gtr2p, are involved in epigenetic control of gene expression in Saccharomyces cerevisiae.
abstract: Gtr1p and Gtr2p of Saccharomyces cerevisiae are members of the Ras-like GTP binding family and interact genetically with Prp20p (yeast RCC1), which is a guanine nucleotide exchange factor for Gsp1p (yeast homolog of Ran, involved in nuclear export). Recently, Gtr1p and Gtr2p were suggested to be molecular switches in the rapamycin-sensitive TOR signaling pathway. Here, we show that Gtr1p and Gtr2p genetically interact with the chromatin remodeling factor Ino80p. Gtr2p interacted physically with both Rvb1p and Rvb2p. Consistent with these results, Gtr2p localized to chromatin and could activate transcription. Gtr1p and Gtr2p were found to be involved in chromatin silencing in the vicinity of telomeres. Gtr1p and Gtr2p were required to repress nitrogen catabolite-repressed genes, which are repressed by the TOR signaling pathway. We propose that Gtr1p and Gtr2p are involved in epigenetic control of gene expression in the TOR signaling pathway.
authors.affiliation: Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hayashi
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Wang
authors.forename: Hideki
authors.initials: H
authors.lastname: Kobayashi
mesh_terms: D044127:Epigenesis, Genetic / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*
chemical_list: C121263:GTR2 protein, S cerevisiae; C121262:Gtr1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; C500749:target of rapamycin protein, S cerevisiae; D020559:Monomeric GTP-Binding Proteins