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Phosphatidic acid (PA) is produced rapidly in agonist-stimulated cells, but the physiological function of this PA is unknown. We have examined the effects of PA on distinct isoforms of protein kinase C (PKC) using a new cell-free assay system. Addition of PA to cytosol from COS cells overexpressing PKC-alpha, -epsilon or -zeta differentially-activated all(More)
p74raf-1, a serine/threonine kinase, is structurally related to the protein kinase C (PKC) family and contains a cysteine motif in its N-terminal domain, which is essential for its regulation. It has been shown that p74raf-1 functions upstream of mitogen-activated protein (MAP) kinase kinase. We have constructed a p74raf-1 mutant (N delta raf) that only(More)
Diacylglycerol kinases are involved in cell signaling, either as regulators of diacylglycerol levels or as intracellular signal-generating enzymes. However, neither their role in signal transduction nor their biochemical regulation has been elucidated. Hepatocyte growth factor (HGF), upon binding to its tyrosine kinase receptor, activates multiple signaling(More)
Control of coccidiosis in chickens has relied upon managerial measurements and the prophylactic use of coccidiostatic drugs. With the emergence of Eimeria strains that are resistant to these drugs the use and number of commercially available vaccines has increased. In this review various aspects that contribute to the development of coccidiosis are(More)
Fusion of yellow fluorescent protein (YFP) to the N-terminus of the Escherichia coli Tn10 tet repressor (TetR) created a functional YFP-TetR repressor with the capacity of 88-fold repression of transcription when expressed in Toxoplasma gondii. As a test promoter we used the T. gondii ribosomal protein RPS13 promoter for which we provide experimental(More)
Recently we showed that de novo ribosome biosynthesis is transcriptionally regulated in Coccidia, depending on their life-cycle stage. Since the expression of ribosomal protein genes is likely coordinated, the transcriptional control of all Toxoplasma gondii ribosomal protein (RP) genes was analysed. Therefore, the complete set of all cytoplasmic RPs was(More)
The role of diacylglycerol (DG) formation from phosphatidylcholine in mitogenic signal transduction is poorly understood. We have generated this lipid at the plasma membrane by treating Rat-1 fibroblasts with bacterial phosphatidylcholine-specific phospholipase C (PC-PLC). This treatment leads to activation of mitogen-activated protein kinase (MAPK).(More)
East Coast fever (ECF) in cattle is caused by the tick-borne protozoan parasite Theileria parva. The major sporozoite surface antigen of T. parva (p67) is an important candidate for inclusion in a subunit vaccine. Recently, we reported the expression and production of different parts of p67 as fusions to either GFP or to the baculovirus GP64 envelope(More)
In signal transduction, diacylglycerol (DG) kinase attenuates levels of the second messenger DG by converting it to phosphatidic acid. A previously cloned full-length human 86 kDa DG kinase cDNA was expressed as fusion protein in Escherichia coli, to aid in the generation of DG-kinase-specific monoclonal antibodies suitable for immunoprecipitation(More)
Diacylglycerol (DG) kinase attenuates the level of the second messenger DG in signal transduction, and therefore possibly modulates protein kinase C (PKC). DG kinase was purified to homogeneity from human white blood cells, showing an Mr of 86 kDa as determined by SDS-PAGE and gel filtration. Two amino acid sequences of tryptic peptides from DG kinase were(More)