Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activation of membrane-bound phospholipase D (PLD) resulting in the generation of phosphatidic acid (PA) is increasingly recognized as an integral event in the initiation of a variety of cellular responses. We explored whether alpha-thrombin is a physiologic agonist for PLD activation in human umbilical vein endothelial cells (HUVEC). HUVEC monolayers were labeled with [32Pi] and PLD activity determined by formation of the PLD metabolite [32P] phosphatidylethanol (PEt) in the presence of 5 g/L ethanol by thin-layer chromatography. alpha-Thrombin rapidly (1 minute) increased PA and PEt formation in a dose-dependent manner (10(-6) to 10(-10)) with maximal PLD stimulation achieved with 10 nmol/L alpha-thrombin producing a threefold to fourfold increase in PA and a sixfold to eightfold increase in PEt over controls at 15 minutes. Esterolytically active zeta-thrombin (10 nmol/L) and gamma-thrombin (1 mumol/L), but not inactive DIP-alpha-thrombin (1 mumol/L) also increased PLD activity. The role of Ca2+ flux in human endothelial cell PLD activation was investigated and PEt formation was significantly enhanced by Ca2+ ionophores A23187 and ionomycin (1 mumol/L, three-fold to fourfold increase in PEt). Alpha-Thrombin-stimulated PEt formation was abolished (greater than 90% inhibition) with chelation of intracellular calcium (Ca2+i) by pretreatment with BAPTA-AM (25 mumol/L, 30 minutes) but only mildly attenuated (30% inhibition) by removal of extracellular calcium (Ca2+E) with EGTA (5 mmol/L). The protein kinase C (PKC) inhibitor staurosporine reduced alpha-thrombin-induced PEt formation in a dose-dependent manner (10 mumol/L, 78% inhibition) and PKC downregulation with chronic PMA treatment (18 hours) also resulted in marked inhibition of alpha-thrombin-induced PEt formation. Neither pertussis nor botulinum C bacterial toxins significantly altered alpha-thrombin-induced PLD responses. In contrast, similar pretreatment with cholera toxin (1 microgram/mL, 60 minutes) consistently augmented alpha-thrombin-stimulated PLD activity by 50% to 90%. Comparable results were observed with agents which increased cAMP such as forskolin, 8-bromo cAMP, or dibutyryl cAMP and cholera toxin augmentation was abolished by 2-dideoxyadenosine, a competitive inhibitor of adenylyl cyclase activity. These studies demonstrate that alpha-thrombin is a potent stimulus for human PLD-mediated PA formation and that cyclic adenosine nucleotides modulate agonist-induced cellular PLD activity. In this model of PLD activation, alpha-thrombin receptor occupancy leads to the breakdown of phosphatidylinositol 4,5-bisphosphate catalyzed by phospholipase C producing the Ca2+ secretagogue IP3 and DAG.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Thrombin stimulation of human endothelial cell phospholipase D activity. Regulation by phospholipase C, protein kinase C, and cyclic adenosine 3'5'-monophosphate. 131 12

Two G proteins that regulate phosphoinositide phospholipase C in liver plasma membranes have been purified to homogeneity in both the heterotrimeric and dissociated forms. The heterotrimers contain a 42 kDa or 43 kDa alpha subunit and a 35 kDa beta subunit. The alpha subunits are not ADP-ribosylated by pertussis toxin and are closely related immunologically to members of the recently identified Gq class of G proteins. The specific phosphoinositide phospholipase C isozyme that responds to the G proteins has been determined to the beta 1 isozyme. GTP analogues stimulate phosphatidylcholine hydrolysis in rat liver plasma membranes. The nucleotide specificity and Mg2+ dependency of the response indicate that it is mediated by a G protein. Phosphatidic acid, diacylglycerol, choline and phosphorylcholine are the products, indicating that both phospholipase D and C activities are involved. Activation of phospholipase D is also indicated by the enhanced production of phosphatidyl-ethanol in the presence of ethanol.
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PMID:Regulation of phosphoinositide and phosphatidylcholine phospholipases by G proteins. 132 81

In rabbit peritoneal neutrophils prelabeled with [3H] lyso platelet-activating factor, a protein kinase C inhibitor, staurosporine (> 1 microM), increased [3H]phosphatidylethanol ([3H]PEt) level in the presence of ethanol in a concentration- and time-dependent manner, providing evidence for staurosporine activation of phospholipase D (PLD). The staurosporine activation of the enzyme absolutely required both extracellular calcium and cytochalasin B, and was almost completely inhibited by pretreatment of the cells with pertussis toxin (IAP). In a reconstituted system where the purified Gi1 had been incorporated into phospholipid vesicles, staurosporine activated GTPase activity of Gi1 in a concentration-dependent fashion, with a maximal 4-5-fold effect. ADP-ribosylation by IAP of Gi1 in vesicles significantly suppressed the staurosporine activation. As with the GTPase activity of Gi1, GTPase activities of other purified IAP-sensitive G proteins, such as Gi2 and G(o), were significantly stimulated by staurosporine, but the cholera toxin substrate Gs was appreciably less sensitive to the staurosporine stimulation. The staurosporine activation of GTPase was also observed in rabbit neutrophil membranes from control cells, but not in membranes from IAP-treated neutrophils. From these results, we conclude that the staurosporine activation of PLD in rabbit neutrophils is attributed to the direct activation of an IAP-sensitive G protein in a similar manner to receptors occupied by agonists. By contrast, staurosporine failed to activate phosphoinositide-specific phospholipase C (PI-PLC) under the conditions in which it activated PLD, indicating that there exists a PLD activation pathway independent of PI-PLC. Furthermore, it was found that N-acetyl-beta-glucosaminidase release from the granules of intact neutrophils was evoked by staurosporine to almost the same extent as by fMLP (100 nM), but O2- generation was not affected. These results suggest a possibility that PLD pathway plays an important role in enzyme release, but is not sufficient for O2- generation, in rabbit peritoneal neutrophils.
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PMID:A protein kinase C inhibitor, staurosporine, activates phospholipase D via a pertussis toxin-sensitive GTP-binding protein in rabbit peritoneal neutrophils. 133 Oct 88

Bovine adrenal chromaffin cells in culture show an increased formation of [3H]inositol phosphates (after preloading with [3H]inositol) on depolarisation with increased extracellular K+. This increased breakdown of inositol lipid is further increased by the dihydropyridine Ca2+ channel activator BAY K 8644 at nM concentrations, implying that proteins which bind dihydropyridines are involved in this mechanism. Further, pretreatment of adrenal cells with pertussis toxin (100 ng ml-1) prevented the K(+)-induced breakdown of inositol lipids, arguing the involvement of a pertussis toxin-sensitive G protein in the effect. Chronic exposure of bovine adrenal chromaffin cells to a concentration of ethanol which inhibits K(+)-induced breakdown of inositol phospholipid, caused a 70-100% increase in the binding of [3H]DHP sites. In these experiments it was found that excess extracellular Ca2+ would considerably reduce this up-regulation, whereas growth of cells in pertussis toxin closely mimicked the up-regulation obtained by growth of cells in ethanol. These experiments suggest that inhibition of membrane Ca2+ flux, through a G protein-associated channel, is closely involved in the ethanol-induced regulation of [3H]dihydropyridine binding sites. The inositol lipid-protein kinase C second messenger system is also implicated in this regulation, by experiments in which inhibitors of protein kinase C (chronic treatment with phorbol myristyl acetate, or with sphingosine) up-regulated binding sites for [3H]dihydropyridine to a similar extent as that seen with growth in ethanol.
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PMID:Second messengers involved in genetic regulation of the number of calcium channels in bovine adrenal chromaffin cells in culture. 169 2

Pretreatment with pertussis toxin (0.5 and 1.0 microgram/animal, i.c.v., seven days prior to testing) reversed the reduction in locomotor activity in the holeboard test caused by administration of the alpha 2-adrenoceptor agonist, medetomidine (0.1 mg/kg, i.p.). Intrinsic behavioral effects of pertussis toxin treatment were also observed, these included a reduction in exploratory head-dipping and an increase in locomotor activity. These doses of pertussis toxin also reduced the ataxia induced by a 2.4 g/kg dose of ethanol. Pertussis toxin treated animals also exhibited a diminished hypothermic response to ethanol (2 g/kg), although the pertussis toxin treated animals had lower body temperatures prior to ethanol administration compared to sham treated animals. Neither the behavioral effect of pertussis holotoxin in the holeboard nor its effects on reversing medetomidine hypolocomotion or ethanol-induced ataxia were seen following administration of the binding oligomer of pertussis toxin which binds to the cell membrane but does not possess the enzymatically active subunit. These findings implicate mechanisms involving pertussis toxin sensitive G-proteins in modulating some behavioral and physiological effects of ethanol.
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PMID:Interactions of intracerebroventricular pertussis toxin treatment with the ataxic and hypothermic effects of ethanol. 194 14

The effect of ethanol on GTP-binding protein of cortical adenylate cyclase (AC) system in the Wistar and Fischer 344 rats was examined. In both Wistar and Fischer 344 rats, ethanol (100mM) potentiated Gpp (NH) p-stimulated AC activity and decreased EC50 for Gpp (NH)p in the cerebral cortical membrane (CCM). Ethanol treatment also augmented Mn-stimulated AC activity in Wistar CCM, whereas there was no significant change in Fischer 344 CCM. IC50 calculated from the Gpp (NH)p (0.01-0.3 microM) inhibition of forskolin-stimulated AC was decreased by ethanol treatment in Wistar CCM, but this was not the case in Fischer 344 CCM. There was no appreciable change in ADP-ribosylation of Gs and Gi in CCM with pertussis or cholera toxin. These results suggest that ethanol in vitro enhances the Gi function as well as affecting the Gs function in Wistar rat cortical AC system, and the effect of ethanol on Gi protein are different in Wistar and Fischer 344 CCM.
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PMID:[Effects of ethanol on GTP binding protein function in rat cerebral cortex: strain difference between Wistar and Fischer 344 rats]. 212 Nov 24

The interaction of ethanol with GABAB-receptor system and the selectivity of phaclofen for GABA-receptor subtypes were investigated by employing an in vitro model of 36Cl-influx assay in mammalian cultured neurons and also in vivo models of picrotoxin- and NMDA-induced convulsions in rats. Ethanol (20 mM), without having any effect per se, potentiated the effect of GABA on 36Cl-influx, whereas at concentration 50 mM, ethanol activated Cl(-)-channels directly in mice spinal cord cultured neurons. In contrast, (-)baclofen (100 microM) did not modify the effects of GABA or ethanol on 36Cl-influx. Similarly, phaclofen (500 microM), as well as pertussis toxin (140 ng/ml, overnight incubation) did not modify these effects. Interestingly, phaclofen (200 micrograms i.c.v.) reversed the anticonvulsant effect of ethanol, but not that of pentobarbital or diazepam or progabide, against picrotoxin-induced convulsions in rats. However, phaclofen failed to modify the anticonvulsant effect of ethanol against NMDA-induced convulsions. These observations indicate that phaclofen is devoid of GABAA-receptor blockade property, and the anticonvulsant effect of ethanol against picrotoxin may be mediated through the activation of both GABA-receptor subtypes.
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PMID:Are GABAB receptors involved in the pharmacological effects of ethanol? 217 47

The effects of ethanol on the beta adrenergic receptor-coupled adenylate cyclase system were examined in vitro using membranes prepared from S49 lymphoma cells. Ethanol caused a dose-dependent increase in adenylate cyclase activity in membranes prepared from wild-type cells when the activity was measured in the presence of GTP. Activity measured in the presence of isoproterenol was also increased by ethanol, but the fold-stimulation by isoproterenol was lower in the presence of ethanol. Ethanol also shifted the dose-response curve for stimulation of the enzyme by isoproterenol to the right. This shift was due to a decrease in the affinity of the beta adrenergic receptor for isoproterenol. A decrease in the affinity of the receptor for the antagonists [125I]iodopindolol and propranolol was also observed, but the magnitude of this effect was less than that seen with the agonist isoproterenol. The density of binding sites for [125I]iodopindolol was not affected by ethanol. Dose-response curves for NaF and guanosine-5'-O-(3-thiotriphosphate), both of which stimulate adenylate cyclase activity through an effect on the stimulatory guanine nucleotide-binding protein (Gs), were shifted to the left by the addition of ethanol. In membranes prepared from the CYC- variant of S49 cells, which lacks the alpha subunit of Gs, guanosine-5'-O-(3-thiotriphosphate) inhibited forskolin-stimulated adenylate cyclase activity. The inhibition by guanosine-5'-O-(3-thiotriphosphate) was not affected by ethanol. In membranes prepared from both wild-type and CYC- S49 cells, ethanol inhibited forskolin-stimulated adenylate cyclase activity. Whereas the inhibition of this activity by GTP was greatly attenuated in membranes prepared from CYC- S49 cells which had been pretreated with pertussis toxin, the inhibition by ethanol was not affected by pretreatment with pertussis toxin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of ethanol in vitro on the beta adrenergic receptor-coupled adenylate cyclase system. 284 25

The outer membrane (OM) component(s) from Bordetella pertussis which potentiated the antigenicity of purified Haemophilus influenzae type b capsular polysaccharide, polyribosyl ribitol phosphate (PRP), has been isolated and partially characterized. The OM was isolated from spheroplasting medium by precipitating at pH 5.0; fractionation was carried out by dissolving the crude OM in Triton X-100 followed by selective precipitation of OM in 50% ethanol. Further purification of OM was accomplished by DEAE-Sepharose 6BCL and Sephacryl S-300 chromatography. The biochemical composition and protein profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis of various OM preparations have been examined. Combined vaccines consisting of OM components and PRP were given to young Sprague-Dawley rats, and the serum antibody to PRP was measured by an [3H]PRP binding assay. The purified OM containing mainly a 30,000-dalton protein, but not purified lipopolysaccharide or leukocytosis-promoting toxin, exhibited strong enhancement of PRP immunogenicity.
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PMID:Isolation of the outer membrane components of Bordetella pertussis which enhance the immunogenicity of Haemophilus influenzae type b capsular polysaccharide polyribosyl ribitol phosphate. 286 92

The acute in vitro effects of ethanol on cerebral cortical adenylate cyclase activity and beta-adrenergic receptor characteristics suggested a site of action of ethanol at Gs, the stimulatory guanine nucleotide binding protein. After chronic ethanol ingestion, the beta-adrenergic receptor appeared to be uncoupled (i.e., the form of the receptor with high affinity for agonist was undetectable), and stimulation of adenylate cyclase activity by isoproterenol or guanine nucleotides was reduced, suggesting an alteration in the properties of Gs. To further characterize this change, cholera and pertussis toxin-mediated 32P-ADP-ribosylation of mouse cortical membranes was assessed in mice that had chronically ingested ethanol in a liquid diet. 32P-labeled proteins were separated by SDS-PAGE and quantitated by autoradiography. There was a selective 30-50% decrease in cholera toxin-induced labeling of 46 kDa protein band in membranes of ethanol-fed mice, with no apparent change in pertussis toxin-induced labeling. The 46 kDa protein has a molecular weight similar to that of the alpha subunit of Gs, suggesting a reduced amount of this protein or a change in its characteristics as a substrate for cholera toxin-induced ADP-ribosylation in cortical membranes of ethanol-fed mice.
Adv Alcohol Subst Abuse 1988
PMID:Cholera toxin-induced ADP-ribosylation of a 46 kDa protein is decreased in brains of ethanol-fed mice. 314 19


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