RRC ID 878
Author Auesukaree C, Tochio H, Shirakawa M, Kaneko Y, Harashima S.
Title Plc1p, Arg82p, and Kcs1p, enzymes involved in inositol pyrophosphate synthesis, are essential for phosphate regulation and polyphosphate accumulation in Saccharomyces cerevisiae.
Journal J. Biol. Chem.
Abstract In Saccharomyces cerevisiae, the phosphate signal transduction PHO pathway is involved in regulating several phosphate-responsive genes such as PHO5, which encodes repressible acid phosphatase. In this pathway, a cyclin-dependent kinase inhibitor (Pho81p) regulates the kinase activity of the cyclin-cyclin-dependent kinase complex Pho80p-Pho85p, which phosphorylates the transcription factor Pho4p in response to intracellular phosphate levels. However, how cells sense phosphate availability and transduce the phosphate signal to Pho81p remains unknown. To identify additional components of the PHO pathway, we have screened a collection of yeast deletion strains. We found that disruptants of PLC1, ARG82, and KCS1, which are involved in the synthesis of inositol polyphosphate, and ADK1, which encodes adenylate kinase, constitutively express PHO5. Each of these factors functions upstream of Pho81p and negatively regulates the PHO pathway independently of intracellular orthophosphate levels. Overexpression of KCS1, but not of the other genes, suppressed PHO5 expression in the wild-type strain under low phosphate conditions. These results raise the possibility that diphosphoinositol tetrakisphosphate and/or bisdiphosphoinositol triphosphate may be essential for regulation of the PHO pathway. Furthermore, the Deltaplc1, Deltaarg82, and Deltakcs1 deletion strains, but not the Deltaipk1 deletion strain, had significantly reduced intracellular polyphosphate levels, suggesting that enzymes involved in inositol pyrophosphate synthesis are also required for polyphosphate accumulation.
Volume 280(26)
Pages 25127-33
Published 2005-7-1
DOI 10.1074/jbc.M414579200
PII M414579200
PMID 15866881
MeSH Adenosine Triphosphate / chemistry Blotting, Northern Fungal Proteins / chemistry Gene Deletion Gene Expression Regulation, Fungal* Genome Inositol / metabolism* Inositol Phosphates / chemistry Magnetic Resonance Spectroscopy Models, Biological Open Reading Frames Phosphates / chemistry Phosphatidylinositol Diacylglycerol-Lyase / chemistry Phosphatidylinositol Diacylglycerol-Lyase / physiology* Phosphorylation Phosphotransferases (Alcohol Group Acceptor) / chemistry Phosphotransferases (Alcohol Group Acceptor) / physiology* Phosphotransferases (Phosphate Group Acceptor) Plasmids / metabolism Polyphosphates / chemistry RNA / metabolism Saccharomyces cerevisiae / metabolism* Saccharomyces cerevisiae Proteins / chemistry* Saccharomyces cerevisiae Proteins / physiology* Signal Transduction
IF 4.106
Times Cited 49
Yeast BY23849(BY4741) BY23850(BY4742) BY21447(PHY77) BY21448(PHY253) BY21449(PHY86) BY21451(PHY104) BY21452(PHY116) BY21453(PHY121) BY21454(PHY129) BY21455(PHY174) etc.