title: Phosphatidylinositol-4-phosphate 5-kinase activity is stimulated during temperature-induced morphogenesis in Candida albicans.
abstract: Phosphoinositides are important lipid signalling molecules in eukaryotic cells. Phosphatidylinositol-4-phosphate 5-kinase (PI4P5K) catalyses the production of phosphatidylinositol 4,5-bisphosphate (PIP2), which stimulates phospholipase D1 (PLD1) activity in mammalian and yeast cells. PLD1 catalyses the formation of phosphatidic acid (PA), which has been shown to activate PI4P5Ks in mammalian and Saccharomyces cerevisiae cells. In the present study, PI4P5K activity in the opportunistic pathogen Candida albicans was identified. A gene with significant sequence homology to the S. cerevisiae PI4P5K was cloned and designated MSS4. This gene was demonstrated to encode a functional PI4P5K by expression in S. cerevisiae. This enzyme was found to be membrane-associated and was stimulated by PA. Within the first 20 min after induction of polarized hyphal growth induced by a shift to elevated temperature, PI4P5K activity increased 2.5-fold. This stimulation was not observed when hyphae were induced by a combination of elevated temperature and serum. A lack of PLD1 activity resulted in the loss of induction of PI4P5K activity during the morphogenetic switch. Furthermore, the addition of propranolol attenuated the stimulation of PI4P5K activity during morphogenesis. These results suggest that PA derived from PLD1 activity stimulates C. albicans PI4P5K during the switch to the hyphal form under some conditions.
authors.affiliation: Molecular and Cellular Biology Program1, Division of Mycology2, Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, PO Box 250504, Charleston, SC 29403, USA.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Hairfield
authors.affiliation: Molecular and Cellular Biology Program1, Division of Mycology2, Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, PO Box 250504, Charleston, SC 29403, USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Westwater
authors.affiliation: Molecular and Cellular Biology Program1, Division of Mycology2, Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, PO Box 250504, Charleston, SC 29403, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Dolan
mesh_terms: D000595:Amino Acid Sequence; D002176:Candida albicans / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D002462:Cell Membrane / Q000201:enzymology; D004790:Enzyme Induction / Q000187:drug effects; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal / Q000235:genetics; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000187:drug effects; D010641:Phenotype; D010712:Phosphatidic Acids / Q000494:pharmacology; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011433:Propranolol / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013696:Temperature
chemical_list: D010712:Phosphatidic Acids; D011433:Propranolol; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D010739:Phospholipase D; C106801:phospholipase D1