@article {34,
	title = {Transcription regulation of the Saccharomyces cerevisiae PIS1 gene by inositol and the pleiotropic regulator, Ume6p.},
	journal = {Mol Microbiol},
	volume = {70},
	year = {2008},
	month = {2008 Dec},
	pages = {1529-39},
	abstract = {In Saccharomyces cerevisiae, transcription of most of the phospholipid biosynthetic genes (e.g. INO1, CHO1, CHO2 and OPI3) is repressed by growth in the presence of inositol and choline and derepressed in their absence. This regulation requires the Ino2p and Ino4p activators and the Opi1p repressor. The PIS1 structural gene is required for the synthesis of the essential lipid phosphatidylinositol. Previous reports show that PIS1 expression is uncoupled from inositol/choline regulation, but is regulated by carbon source, hypoxia and zinc. However, in this study we found that the expression of PIS1 is induced twofold by inositol. This regulation did not require Ino2p and Ino4p, although Ino4p was required for full expression. Ino4p is a basic helix-loop-helix protein that requires a binding partner. Curiously, none of the other basic helix-loop-helix proteins affected PIS1 expression. Inositol induction did require another general regulator of phospholipid biosynthesis, Ume6p. Ume6p was found to be a positive regulator of PIS1 gene expression. Ume6p, and several associated factors, were required for inositol-mediated induction and chromatin immunoprecipitation analysis showed that Ume6p directly regulates PIS1 expression. Thus, we demonstrate novel regulation of the PIS1 gene by Ume6p.},
	keywords = {Chromatin Immunoprecipitation, DNA-Binding Proteins, Gene Expression Regulation, Fungal, Histone Deacetylases, Inositol, Repressor Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Transcription, Genetic, Transferases (Other Substituted Phosphate Groups)},
	issn = {1365-2958},
	doi = {10.1111/j.1365-2958.2008.06506.x},
	author = {Jani, Niketa M and Lopes, John M}
}
@article {42,
	title = {Expression of the yeast PIS1 gene requires multiple regulatory elements including a Rox1p binding site.},
	journal = {J Biol Chem},
	volume = {278},
	year = {2003},
	month = {2003 Oct 3},
	pages = {38646-52},
	abstract = {The PIS1 gene is required for de novo synthesis of phosphatidylinositol (PI), an essential phospholipid in Saccharomyces cerevisiae. PIS1 gene expression is unusual because it is uncoupled from the other phospholipid biosynthetic genes, which are regulated in response to inositol and choline. Relatively little is known about regulation of transcription of the PIS1 gene. We reported previously that PIS1 transcription is sensitive to carbon source. To further our understanding of the regulation of PIS1 transcription, we carried out a promoter deletion analysis that identified three regions required for PIS1 gene expression (upstream activating sequence (UAS) elements 1-3). Deletion of either UAS1 or UAS2 resulted in an approximately 45\% reduction in expression, whereas removal of UAS3 yielded an 84\% decrease in expression. A comparison of promoters among several Saccharomyces species shows that these sequences are highly conserved. Curiously, the UAS3 element region (-149 to -138) includes a Rox1p binding site. Rox1p is a repressor of hypoxic genes under aerobic growth conditions. Consistent with this, we have found that expression of a PIS1-cat reporter was repressed under aerobic conditions, and this repression was dependent on both Rox1p and its binding site. Furthermore, PI levels were elevated under anaerobic conditions. This is the first evidence that PI levels are affected by regulation of PIS1 transcription.},
	keywords = {Anoxia, Base Sequence, Binding Sites, Carbon, Chloramphenicol O-Acetyltransferase, Choline, Chromatography, Thin Layer, Conserved Sequence, DNA, DNA, Complementary, DNA-Binding Proteins, Gene Deletion, Gene Expression Regulation, Fungal, Genes, Reporter, Inositol, Lipid Metabolism, Models, Biological, Models, Genetic, Molecular Sequence Data, Oxygen, Phospholipids, Plasmids, Promoter Regions, Genetic, Protein Binding, Repressor Proteins, RNA, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Transcription, Genetic, Transferases (Other Substituted Phosphate Groups)},
	issn = {0021-9258},
	doi = {10.1074/jbc.M305251200},
	author = {Gardocki, Mary Elizabeth and Lopes, John M}
}
@article {43,
	title = {Opi1p, Ume6p and Sin3p control expression from the promoter of the INO2 regulatory gene via a novel regulatory cascade.},
	journal = {Mol Microbiol},
	volume = {48},
	year = {2003},
	month = {2003 May},
	pages = {823-32},
	abstract = {The INO2 gene of Saccharomyces cerevisiae is required for expression of most of the phospholipid biosynthetic genes. INO2 expression is regulated by a complex cascade that includes autoregulation, Opi1p-mediated repression and Ume6p-mediated activation. To screen for mutants with altered INO2 expression directly, we constructed an INO2-HIS3 reporter that provides a plate assay for INO2 promoter activity. This reporter was used to isolate mutants (dim1) that fail to repress expression of the INO2 gene in an otherwise wild-type strain. The dim1 mutants contain mutations in the OPI1 gene. To define further the mechanism for Ume6p regulation of INO2 expression, we isolated suppressors (rum1, 2, 3) of the ume6Delta mutation that overexpress the INO2-HIS3 gene. Two of the rum mutant groups contain mutations in the OPI1 and SIN3 genes showing that opi1 and sin3 mutations are epistatic to the ume6Delta mutation. These results are surprising given that Ume6p, Sin3p and Rpd3p are known to form a complex that represses the expression of a diverse set of yeast genes. This prompted us to examine the effect of sin3Delta and rpd3Delta mutants on INO2-cat expression. Surprisingly, the sin3Delta allele overexpressed INO2-cat, whereas the rpd3Delta mutant had no effect. We also show that the UME6 gene does not affect the expression of an OPI1-cat reporter. This suggests that Ume6p does not regulate INO2 expression indirectly by regulating OPI1 expression.},
	keywords = {Basic Helix-Loop-Helix Transcription Factors, DNA-Binding Proteins, Fungal Proteins, Gene Expression Regulation, Fungal, Genes, Regulator, Genes, Reporter, Genetic Complementation Test, Histone Deacetylases, Methyltransferases, Phenotype, Phospholipids, Promoter Regions, Genetic, Repressor Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Transcription Factors},
	issn = {0950-382X},
	author = {Kaadige, Mohan R and Lopes, John M}
}
