title: Regulation of phosphatidic acid levels in Trypanosoma cruzi.
abstract: Lipid kinases and phosphatases play essential roles in signal transduction processes involved in cytoskeletal rearrangement, membrane trafficking, and cellular differentiation. Phosphatidic acid (PtdOH) is an important mediator lipid in eukaryotic cells, but little is known regarding its regulation in the parasite Trypanosoma cruzi, an agent of Chagas disease. In order to clarify the relationship between PtdOH metabolism and developmental stages of T. cruzi, epimastigotes in culture were subjected to hyperosmotic stress (~1,000 mOsm/L), mimicking the environment in the rectum of vector triatomine bugs. These experimental conditions resulted in differentiation to an intermediate form between epimastigotes and trypomastigotes. Morphological changes of epimastigotes were correlated with an increase in PtdOH mass accomplished by increased enzyme activity of diacylglycerol kinase (DAGK, E.C. 2.7.1.107) and concomitant decreased activity of phosphatidate phosphatases type 1 and type 2 (PAP1, PAP2, E.C. 3.1.3.4). Our results indicate progressive increases of PtdOH levels during the differentiation process, and suggest that the regulation of PtdOH metabolism is an important mechanism in the transition from T. cruzi epimastigote to intermediate form.
authors.affiliation: Química Biológica, FCEFQN, Universidad Nacional de Río Cuarto, X5804BYA, Río Cuarto, Córdoba, Argentina.
authors.forename: Alba Marina
authors.initials: AM
authors.lastname: Gimenez
authors.forename: Verónica S
authors.initials: VS
authors.lastname: Santander
authors.forename: Ana L
authors.initials: AL
authors.lastname: Villasuso
authors.forename: Susana J
authors.initials: SJ
authors.lastname: Pasquaré
authors.forename: Norma M
authors.initials: NM
authors.lastname: Giusto
authors.forename: Estela E
authors.initials: EE
authors.lastname: Machado
mesh_terms: D000595:Amino Acid Sequence; D014355:Chagas Disease / Q000469:parasitology*; D019852:Diacylglycerol Kinase / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D000073718:Pancreatitis-Associated Proteins; D010711:Phosphatidate Phosphatase / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000254:growth & development* / Q000378:metabolism
chemical_list: D000073718:Pancreatitis-Associated Proteins; D010712:Phosphatidic Acids; C000612141:REG3A protein, human; D019852:Diacylglycerol Kinase; D010711:Phosphatidate Phosphatase