title: Type 2C protein phosphatase Ptc6 participates in activation of the Slt2-mediated cell wall integrity pathway in Saccharomyces cerevisiae.
abstract: The phosphorylation status of cellular proteins results from an equilibrium between the activities of protein kinases and protein phosphatases (PPases). Reversible protein phosphorylation is an important aspect of signal transduction that regulate many biological processes in eukaryotic cells. The Saccharomyces cerevisiae genome encodes 40 PPases, including seven members of the protein phosphatase 2C subfamily (PTC1 to PTC7). In contrast to other PPases, the cellular roles of PTCs have not been investigated in detail. Here, we sought to determine the cellular role of PTC6 in S. cerevisiae with disruption of PTC genes. We found that cells with Δptc6 disruption were tolerant to the cell wall-damaging agents Congo red (CR) and calcofluor white (CFW); however, cells with simultaneous disruption of PTC1 and PTC6 were very sensitive to these agents. Thus, simultaneous disruption of PTC1 and PTC6 gave a synergistic response to cell wall damaging agents. The level of phosphorylated Slt2 increased significantly after CR treatment in Δptc1 cells and more so in Δptc1Δptc6 cells; therefore, deletion of PTC6 enhanced Slt2 phosphorylation in the Δptc1 disruptant. The level of transcription of KDX1 upon exposure to CR increased to a greater extent in the Δptc1Δptc6 double disruptant than the Δptc1 single disruptant. The Δptc1Δptc6 double disruptant cells showed normal vacuole formation under standard growth conditions, but fragmented vacuoles were present in the presence of CR or CFW. Our analyses indicate that S. cerevisiae PTC6 participates in the negative regulation of Slt2 phosphorylation and vacuole morphogenesis under cell wall stress conditions.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Dilruba
authors.initials: D
authors.lastname: Sharmin
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sasano
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Minetaka
authors.initials: M
authors.lastname: Sugiyama
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: harashima@bio.eng.osaka-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Harashima
mesh_terms: D001557:Benzenesulfonates / Q000494:pharmacology; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism*; D003224:Congo Red / Q000494:pharmacology; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D008031:Lignin / Q000378:metabolism; D054892:Metagenome / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009699:N-Glycosyl Hydrolases / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000235:genetics; D016601:RNA-Binding Proteins; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014158:Transcription, Genetic; D014617:Vacuoles / Q000378:metabolism
chemical_list: D001557:Benzenesulfonates; C080988:MLP1 protein, S cerevisiae; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C036909:lignocellulose; D003224:Congo Red; C007061:C.I. Fluorescent Brightening Agent 28; D008031:Lignin; D020928:Mitogen-Activated Protein Kinases; C072724:SLT2 protein, S cerevisiae; C518822:PTC6 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D043364:Endo-1,4-beta Xylanases; D009699:N-Glycosyl Hydrolases
keywords: Functional redundancy; PTC6; Protein phosphatase 2C; Saccharomyces cerevisiae; Slt2 pathway; Stress response