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

We have investigated the mechanisms underlying prostaglandin inhibition of histamine-stimulated parietal cell function. Enzyme-dispersed canine parietal cells were enriched by elutriation. The accumulation of the weak base [14C]aminopyrine was used as an index of parietal cell function and cyclic adenosine monophosphate content was measured by radioimmunoassay. Step density gradients of the elutriator-enriched parietal cell fractions indicated that parietal cells accounted for the histamine stimulation of cyclic adenosine monophosphate production and inhibition by the prostaglandin E analogue Enprostil. Pertussis toxin adenosine diphosphate-ribosylates a subunit with a molecular weight of 41,000, thereby inactivating the inhibitory guanine nucleotide-binding protein of adenylate cyclase. Pertussis toxin treatment of parietal cells in overnight suspension culture was used to determine if inhibitory guanosine triphosphate-binding protein mediated prostanoid inhibition. In control cultured cells, prostaglandin E2 and Enprostil markedly inhibited forskolin- and histamine-stimulated aminopyrine accumulation. In parietal cells treated with pertussis toxin (300 ng/ml) for 18 h, stimulation of parietal cell function by histamine, isobutylmethylxanthine, and forskolin was unaltered compared with control cells, whereas prostaglandin E2 and Enprostil inhibition was markedly reduced. In pertussis toxin-treated cells, histamine-stimulated cyclic adenosine monophosphate generation was unaltered, whereas Enprostil inhibition of histamine-stimulated cyclic adenosine monophosphate production was markedly reduced. Pertussis toxin treatment of membranes from control, but not from pertussis toxin-treated, cells induced the [32P]adenosine diphosphate-ribosylation of a membrane protein with a molecular weight of 41,000, presumably the alpha-subunit of inhibitory guanosine triphosphate-binding protein. We conclude that prostanoids inhibit parietal cell function by receptor-mediated interaction with the inhibitory guanine nucleotide-binding protein of adenylate cyclase.
...
PMID:Prostanoid inhibition of canine parietal cells: mediation by the inhibitory guanosine triphosphate-binding protein of adenylate cyclase. 283 42

Isolated human polymorphonuclear (PMN) leukocyte plasma membranes express high affinity (mean Kd = 0.12 nM) and low affinity (mean Kd = 50 nM) receptors for the chemotactic factor leukotriene B4 (5(S),12(R)-dihydroxy-eicosa-6,14 cis-8,10 trans-tetraenoic acid; LTB4) that are similar to those on intact PMN leukocytes. A portion of high affinity LTB4-R on PMN leukocyte membranes were converted to the low affinity state by GTP (mean +/- SE = 28.6 +/- 14.0%) and nonhydrolyzable GTP analogues, such as 5'-guanylylimidodiphosphate (GMP-PNP), in a concentration-dependent, nucleotide-specific, and reversible manner, without altering the intrinsic binding affinities of either class. [3H]GMP-PNP bound specifically to one class of receptors (mean Kd = 13 nM) on PMN leukocyte membranes. The interdependence of the LTB4-binding membrane protein and guanine nucleotide-binding protein was suggested by the capacity of LTB4 to enhance by a maximum of 150% the binding of [3H]GMP-PNP to PMN leukocyte membranes by increasing the number, but not altering the affinity, of receptors for GMP-PNP. Pertussis toxin, but not cholera toxin, reversed the enhancement of binding of [3H]GMP-PNP produced by LTB4. Guanine nucleotide-binding proteins and high affinity LTB4-R thus exhibit a mutual regulation that differs mechanistically from that of peptide chemotactic factor receptors on PMN leukocytes.
...
PMID:Selective modulation by guanine nucleotides of the high affinity subset of plasma membrane receptors for leukotriene B4 on human polymorphonuclear leukocytes. 283 4

GH exerts a number of metabolic effects on adipose tissue. Depending on the circumstances, it may increase or decrease glucose metabolism and lipolysis. These effects appear to be mediated by a single class of receptors, which bind GH with high affinity. Incubation of isolated rat adipocytes with a variety of lipolytic agents, including catecholamines, forskolin, or (Bu)2cAMP, decreased the specific binding of [125I]human (h) GH within 10 min. In the presence of 10 microM forskolin, GH binding declined to less than 20% of the control value within 50 min. Cholera and pertussis toxins, which increase cAMP secondary to ADP ribosylation of guanine nucleotide-binding proteins associated with hormone receptors, also decreased the binding of GH. None of these agents affected the rate of loss of cell-associated 125I when added to cells that had previously equilibrated with [125I]hGH. The inhibitory effects of forskolin and (Bu)2cAMP were at least as great when binding was measured in the presence of the protease inhibitor leupeptin, suggesting that increased rates of internalization and processing of bound hormone could not account for the decline in binding. Scatchard plots of data obtained in the presence of forskolin or (Bu)2cAMP were linear and parallel to control plots, indicating that the decline in binding could be accounted for by a decrease in the number of binding sites, with no change in affinity. To determine whether phosphorylation affected binding to receptors already present in the membrane or modified the turnover of receptors, we studied adipocyte ghosts, whose cellular apparatus for receptor turnover is disrupted. Incubation of adipocyte ghosts with cAMP-dependent protein kinase decreased the binding of [125I]hGH by 25%. The data suggest that cAMP-dependent phosphorylation of the GH receptor or a closely associated membrane protein renders the receptor incapable of binding GH.
...
PMID:Adenosine 3',5'-monophosphate-dependent loss of growth hormone binding in rat adipocytes. 283 58

Exposure of FRTL-5 thyroid cells to ATP (1 microM to 1 mM) resulted in the stimulation of I- efflux in association with the induction of inositol trisphosphate production and intracellular Ca2+ mobilization. Nonhydrolyzable ATP derivatives, ADP and GTP, were also as effective in magnitude as ATP, whereas neither AMP nor adenosine exerted significant effect on I- efflux, suggesting a P2-purinergic receptor-mediated activation of I- efflux. Treatment of the cells with the islet-activating protein (IAP) pertussis toxin, which ADP-ribosylated a 41,000 mol wt membrane protein, effectively suppressed the phosphoinositide response to ATP in addition to ATP-dependent I- efflux at agonist concentrations below 10 microM. In contrast, the I- efflux stimulated by TSH, A23187, or phorbol myristate acetate was insusceptible to IAP. The IAP substrate, probably GTP-binding protein, is hence proposed to mediate the activation of P2-purinergic receptor-linked phospholipase-C in FRTL-5 cells. However, the responses to ATP, its nonhydrolyzable derivatives, or ADP at the higher agonist concentrations, especially above 100 microM, were only partially inhibited by IAP, even though the IAP substrate was totally ADP ribosylated by the toxin. The responses to GTP in the whole concentration range tested were not influenced by IAP treatment. Thus, signals arising from the P2-receptor might be transduced to phospholipase-C by two different pathways, i.e. IAP-sensitive and insensitive ones, and result in the stimulation of I- efflux.
...
PMID:Inhibition by islet-activating protein, pertussis toxin, of P2-purinergic receptor-mediated iodide efflux and phosphoinositide turnover in FRTL-5 cells. 284 Feb 60

Muscarinic agonists are potent constrictors of airway smooth muscle. In many tissues, muscarinic agonists also reduce intracellular cyclic AMP by inhibiting its synthesis. In airway smooth muscle, the role muscarinic agonists have in the regulation of cyclic AMP content is not established. The hypothesis of our study was that muscarinic agonists reduce cyclic AMP accumulation in dog tracheal smooth muscle, and that this reduction involves a pertussis toxin-sensitive regulatory protein (Gi) that couples occupancy of the muscarinic receptor by the agonist to inhibition of adenylate cyclase. We measured cyclic AMP accumulation in tracheal smooth muscle from 4 dogs, and found that acetylcholine (10(-4) M) diminished basal and isoproterenol-stimulated cyclic AMP accumulation by 37.6 +/- 12.1% and 39.4 +/- 1.9%, respectively (mean +/- SEM, p less than 0.05). This reduction of cyclic AMP was dose-dependent and inhibited by atropine (10(-5) M). Incubation of dog tracheal smooth muscle with pertussis toxin (12.5 micrograms/ml) for 21 h catalyzed covalent modification of a membrane protein with an approximate Mr of 40,000. In control strips, acetylcholine decreased isoproterenol-stimulated cyclic AMP content by 33.7 +/- 5.6% (p less than 0.05). However, in strips treated with pertussis toxin (10 micrograms/ml), acetylcholine decreased cyclic AMP by only 7.9 +/- 4.8%; this change was not significant. Thus, pertussis toxin (10 micrograms/ml) attenuated muscarinic cholinergic regulation of cyclic AMP. These findings are consistent with muscarinic cholinergic regulation of adenylate cyclase via Gi in dog tracheal smooth muscle. In addition, the techniques we employed should permit the evaluation of other functions of pertussis toxin-sensitive G proteins in airway smooth muscle.
...
PMID:Muscarinic cholinergic inhibition of cyclic AMP accumulation in airway smooth muscle. Role of a pertussis toxin-sensitive protein. 284 36

It was shown that somatostatin (SRIF) inhibited cAMP-dependent vasoactive intestinal peptide (VIP)-stimulated prolactin (PRL) release by a GH3 clonal strain of rat pituitary tumor cells and decreased basal PRL secretion and inhibited PRL release in response to thyrotropin releasing hormone (TRH) whose action was independent of prior synthesis of cAMP. Pretreatment of these cells with pertussis toxin prevented SRIF's inhibitory effects on basal and TRH-stimulated hormone secretion as well as its VIP-stimulated responses. The blockade of SRIF's inhibitory effect on the actions of TRH or VIP was dependent on both the duration of preincubation and concentration of the toxin and was correlated with the ability of the toxin to catalyze the ADP-ribosylation of the 39,000-Da membrane protein. It is likely that this pertussis toxin substrate is involved in signal transduction of SRIF on cAMP-dependent actions of VIP and cAMP-independent action of TRH. However, the mechanism of SRIF's action on TRH is not clear, since SRIF did not affect the intracellular responses by TRH, neither intracellular Ca2+ mobilization nor the increase of 1,2-diacylglycerol formation following the breakdown of polyphosphoinositides.
...
PMID:Pertussis toxin blocks the inhibitory effects of somatostatin on cAMP-dependent vasoactive intestinal peptide and cAMP-independent thyrotropin releasing hormone-stimulated prolactin secretion of GH3 cells. 286 31

The cellular mechanism of action of the cannabimimetic drugs is examined using cultured cells. In membranes from N18TG2 neuroblastoma cells and the neuroblastoma X glioma hybrid cells, NG108-15, the psychoactive cannabinoid drugs and their nantradol analogs could inhibit adenylate cyclase activity. This response was not observed in either the soluble adenylate cyclase from rat sperm or membrane-bound adenylate cyclases from C6 glioma or S49 lymphoma cells. This cellular selectivity provides further evidence for the existence of specific receptors for the cannabimimetic compounds. Receptor-mediated inhibition of adenylate cyclase requires the presence of a guanine nucleotide-binding protein complex, Gi. Gi can be functionally inactivated as a result of an ADP-ribosylation modification catalyzed by pertussis toxin. The present study demonstrates that pertussis toxin treatment of cells abolished the cannabimimetic response in intact cells and in membranes derived therefrom. The action of pertussis toxin required NAD+ as substrate for in vitro modification of neuroblastoma membranes. Furthermore, pertussis toxin was able to catalyze the labeling of a neuroblastoma membrane protein in vitro using [32P] NAD+ under conditions similar to those by which attenuation of the cannabimimetic inhibition of adenylate cyclase could be demonstrated. This evidence demonstrates the requirement for a functional Gi in the action of cannabimimetic drugs.
...
PMID:Involvement of Gi in the inhibition of adenylate cyclase by cannabimimetic drugs. 286 5

Retinoic acid rapidly induces the accumulation of a specific enzyme, tissue transglutaminase (EC 2.3.2.13), in mouse macrophages. We have used the induction of tissue transglutaminase to study the regulation of gene expression by retinoic acid. In this study we report that pertussis toxin can inhibit retinoic acid-induced expression of tissue transglutaminase in mouse resident peritoneal macrophages. This inhibition is paralleled by the ADP-ribosylation of 41,000-dalton macrophage membrane protein.
...
PMID:Pertussis toxin inhibits retinoic acid-induced expression of tissue transglutaminase in macrophages. 287 93

The chronotropic response of the heart to alpha 1-adrenergic catecholamines influenced by pertussis toxin under certain conditions. In view of the fact that alpha 1-adrenergic action is mediated by the phosphatidylinositol pathway of hormone action in many cells, we examined the hypothesis that alpha-adrenergic agonists stimulate phosphatidylinositol hydrolysis in cardiomyocytes and that this effect is sensitive to pertussis toxin. Addition of norepinephrine to cultured rat ventricular myocytes prelabeled with myo-[2-3H]inositol resulted in rapid and significant accumulation of inositol phosphate (IP1) and inositol biphosphate. Norepinephrine-stimulated IP1 formation was not inhibited by propranolol, but was inhibited by alpha-adrenergic antagonists with an order of potency indicating alpha 1-adrenergic receptor subselectivity: prazosin (alpha 1; 3 nM) greater than yohimbine (alpha 2; 10 microM). The effect of norepinephrine to enhance IP1 formation was markedly attenuated in cells pretreated with pertussis toxin. Pertussis toxin also induced the transfer of ADP-ribose from NAD to a 41,000-dalton membrane protein in these cells. The concentration of pertussis toxin resulting in maximal inhibition of norepinephrine-stimulated IP1 formation correlated well with the concentration of pertussis toxin necessary to completely ADP-ribosylate a 41,000-dalton membrane protein (1 ng/ml). The range over which pertussis toxin inhibited norepinephrine-dependent IP1 formation and ADP-ribosylated the 41,000-dalton substrate was virtually identical. These observations establish a role for a 41,000-dalton pertussis toxin substrate in coupling the alpha 1-adrenergic receptor to phosphoinositol hydrolysis in myocardial cells.
...
PMID:A pertussis toxin substrate regulates alpha 1-adrenergic dependent phosphatidylinositol hydrolysis in cultured rat myocytes. 288 98

The S-1 subunit of pertussis toxin was expressed as a fusion protein in a strain of Escherichia coli deficient in protein degradation. The fusion protein reacted with anti-pertussis toxin antibody, and, like authentic pertussis toxin, it ADP-ribosylated a 41,000-molecular-weight membrane protein from human erythrocytes.
...
PMID:Expression of the S-1 catalytic subunit of pertussis toxin in Escherichia coli. 288 25


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>