title: PHO4 transcription factor regulates triacylglycerol metabolism under low-phosphate conditions in Saccharomyces cerevisiae.
abstract: In Saccharomyces cerevisiae, PHM8 encodes a phosphatase that catalyses the dephosphorylation of lysophosphatidic acids to monoacylglycerol and nucleotide monophosphate to nucleoside and releases free phosphate. In this report, we investigated the role of PHM8 in triacylglycerol metabolism and its transcriptional regulation by a phosphate responsive transcription factor Pho4p under low-phosphate conditions. We found that the wild-type (BY4741) cells accumulate triacylglycerol and the expression of PHM8 was high under low-phosphate conditions. Overexpression of PHM8 in the wild-type, phm8Δ and quadruple phosphatase mutant (pah1Δdpp1Δlpp1Δapp1Δ) caused an increase in the triacylglycerol levels. However, the introduction of the PHM8 deletion into the quadruple phosphatase mutant resulted in a reduction in triacylglycerol levels and LPA phosphatase activity. The transcriptional activator Pho4p binds to the PHM8 promoter under low-phosphate conditions, activating PHM8 expression, which leads to the formation of monoacylglycerol from LPA. The synthesized monoacylglycerol is acylated to diacylglycerol by Dga1p, which is further acylated to triacylglycerol by the same enzyme.
authors.affiliation: Lipidomic Centre, Department of Lipid Science, CSIR-Central Food Technological Research Institute (CFTRI), Mysore, Karnataka, 570020, India.|Academy of Scientific and Innovative Research (AcSIR), CSIR-CFTRI Campus.
authors.forename: Kamlesh Kumar
authors.initials: KK
authors.lastname: Yadav
authors.affiliation: Lipidomic Centre, Department of Lipid Science, CSIR-Central Food Technological Research Institute (CFTRI), Mysore, Karnataka, 570020, India.|Academy of Scientific and Innovative Research (AcSIR), CSIR-CFTRI Campus.
authors.forename: Neelima
authors.initials: N
authors.lastname: Singh
authors.affiliation: Lipidomic Centre, Department of Lipid Science, CSIR-Central Food Technological Research Institute (CFTRI), Mysore, Karnataka, 570020, India.|Academy of Scientific and Innovative Research (AcSIR), CSIR-CFTRI Campus.
authors.forename: Ram
authors.initials: R
authors.lastname: Rajasekharan
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D050356:Lipid Metabolism; D008246:Lysophospholipids / Q000235:genetics*; D010710:Phosphates / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D014280:Triglycerides / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D008246:Lysophospholipids; C060292:PHO4 protein, S cerevisiae; D010710:Phosphates; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014280:Triglycerides; C032881:lysophosphatidic acid