title: Phosphorylation of phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxylase (PEPC) in the flesh of fruits.
abstract: This study determined whether phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxylase (PEPC) are phosphorylated in the flesh of a range of fruits. This was done by incubating fruit flesh with32P[P] (where32P[P] =32PO43-), then PEPCK and PEPC were immunoprecipitated from extracts using specific antisera. The incorporation of32P[P] into these enzymes was then determined by autoradiography of SDS-PAGE gels. Both enzymes were subject to phosphorylation in vivo in the flesh of grape, tomato, cherry and plum. PEPCK was also subject to phosphorylation in vivo in developing grape seeds. Proteolytic cleavage of PEPCK showed that it was phosphorylated at a site(s) located on its N-terminal extension. Potentially phosphorylation of these enzymes could contribute to the coordinate regulation of their activities in the flesh of fruits and in developing seeds.
authors: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Italy. Electronic address: rob.walker@talktalk.net.
authors: Robert P
authors: RP
authors: Walker
authors: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Italy.
authors: Andrea
authors: A
authors: Paoletti
authors: Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2 TN, UK.
authors: Richard C
authors: RC
authors: Leegood
authors: Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Italy. Electronic address: franco.famiani@unipg.it.
authors: Franco
authors: F
authors: Famiani
mesh_terms: D018553:Cucumis sativus / Q000201:enzymology / Q000378:metabolism; D005638:Fruit / Q000201:enzymology* / Q000378:metabolism; D018551:Solanum lycopersicum / Q000201:enzymology / Q000378:metabolism; D019684:Magnoliopsida / Q000201:enzymology* / Q000378:metabolism; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000378:metabolism*; D010730:Phosphoenolpyruvate Carboxylase / Q000378:metabolism*; D010761:Phosphorus Radioisotopes / Q000493:pharmacokinetics; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism*; D027861:Prunus / Q000201:enzymology / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000254:growth & development; D014018:Tissue Distribution; D027843:Vitis / Q000201:enzymology / Q000378:metabolism
chemical_list: D010761:Phosphorus Radioisotopes; D010940:Plant Proteins; D010730:Phosphoenolpyruvate Carboxylase; D019764:Phosphoenolpyruvate Carboxykinase (ATP)
keywords: Developing seeds; Fruit; Gluconeogenesis; Malate; Phosphoenolpyruvate carboxykinase; Phosphoenolpyruvate carboxylase; Phosphorylation