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)

Calf serum induced the phospholipase C-mediated hydrolysis of phosphoinositides in normal rat kidney (NRK) cells transformed by a temperature-sensitive Kirsten murine sarcoma virus (tsK-NRK cells). Various growth factors known to induce the phospholipase C reactions in other cell types, such as platelet-derived growth factor, fibroblast growth factor, epidermal growth factor, thrombin, vasopressin, bombesin, cholecystokinin, and prostaglandin F2 alpha, did not induce phospholipase C reactions in the transformed NRK cells. Furthermore, noradrenaline, histamine, dopamine, angiotensin II, carbachol, and tumor growth factor-beta did not induce phospholipase C reactions. However, serotonin did induce phospholipase C reactions. The amount of serotonin contained in the calf serum was sufficient to support 50% of the activity promoted by the serum itself, and calf serum-induced phospholipase C reactions were inhibited to 10-20% of the original level by ketanserin and methysergide, known to be antagonists for the serotonin receptors. Dialysis almost completely removed serotonin from calf serum and reduced the serum-induced phospholipase C reactions. Moreover, the phospholipase C reactions induced by calf serum and serotonin were inhibited by pretreatment of the cells with pertussis toxin or 12-O-tetradecanoylphorbol-13-acetate. These results indicate that serotonin is one of the major serum factors inducing phospholipase C-mediated hydrolysis of phosphoinositides in transformed NRK cells. Serotonin induced phospholipase C reactions not only in tsK-NRK cells but also in nontransformed NRK cells. However, serotonin did not induce these reactions in Swiss 3T3 cells or NIH 3T3 cells.
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PMID:Serotonin as a major serum factor inducing the phospholipase C-mediated hydrolysis of phosphoinositides in normal rat kidney cells. 284 56

Inhibition of renin release by angiotensin II (ANG II) is a calcium-dependent process and is thought to reflect the calcium-mobilizing action of ANG II observed in several tissues. However, in some tissues, such as liver and vascular smooth muscle, ANG II induces cellular responses through inhibition of adenylate cyclase. We examined the possibility that ANG II-induced inhibition of renin release from the kidney is also partly mediated through adenylate cyclase inhibition, by using pertussis toxin (PT), which selectively inactivates the coupling protein Ni, which couples inhibitory hormone receptors to adenylate cyclase. Rats were injected intravenously (i.v.) with 2 micrograms/100 g PT. In isolated kidneys, perfused in an open system with a synthetic medium 3, 5 and 10 days after PT treatment, the inhibition of renin release by ANG II as well as its vasoconstrictor response were significantly attenuated. This effect, which was most pronounced at lower concentrations of ANG II, indicates that ANG II may inhibit renin release partly through inhibition of adenylate cyclase activity.
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PMID:Mode of inhibition of renin release by angiotensin II. 285 14

Thrombin exhibited diverse effects on mouse 3T3 fibroblasts. It (a) decreased cAMP in the cell suspension, (b) inhibited adenylate cyclase in the Lubrol-permeabilized cell suspension in a GTP-dependent manner, increased releases of (c) arachidonic acid and (d) inositol from the cell monolayer prelabeled with these labeled compounds, (e) increased 45Ca2+ uptake into the cell monolayer, and (f) increased 86Rb+ uptake into the cell monolayer in a ouabain-sensitive manner. Most of the effects were reproduced by bradykinin, platelet-activating factor, and angiotensin II. The receptors for these agonists are thus likely to be linked to three separate effector systems: the adenylate cyclase inhibition, the phosphoinositide breakdown leading to Ca2+ mobilization and phospholipase A2 activation, and the Na,K-ATPase activation. Among the effects of these agonists, (a), (b), (c), and (e) were abolished, but (d) and (f) were not, by prior treatment of the cells with islet-activating protein (IAP), pertussis toxin, which ADP-ribosylates the Mr = 41,000 protein, the alpha-subunit of the inhibitory guanine nucleotide regulatory protein (Ni), thereby abolishing receptor-mediated inhibition of adenylate cyclase. The effects (a), (c), (d), and (e) of thrombin, but not (b), were mimicked by A23187, a calcium ionophore. The effects of A23187, in contrast to those of receptor agonists, were not affected by the treatment of cells with IAP. Thus, the IAP substrate, the alpha-subunit of Ni, or the protein alike, may play an additional role in signal transduction arising from the Ca2+-mobilizing receptors, probably mediating process(es) distal to phosphoinositide breakdown and proximal to Ca2+ gating.
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PMID:Receptor-mediated inhibition of adenylate cyclase and stimulation of arachidonic acid release in 3T3 fibroblasts. Selective susceptibility to islet-activating protein, pertussis toxin. 286 Jan 11

The involvement of guanine nucleotide regulatory proteins in the steroidogenic response of the adrenal glomerulosa to angiotensin II (AII) was investigated by analyzing the effects of Bordetella pertussis toxin (PT) on several aspects of AII action. These included receptor binding, stimulation of aldosterone production and GTPase activity, inhibition of cAMP production, and attenuation of the aldosterone response at high angiotensin concentrations. Pretreatment of glomerulosa cells with PT abolished the inhibitory effects of both AII and somatostatin (SRIF) on ACTH-stimulated cAMP production. Under the same incubation conditions, the stimulation of aldosterone secretion by submaximal and maximal steroidogenic concentrations of AII was completely unaffected by the toxin. However, the attenuation of steroid responses seen with supramaximal concentrations of AII was abolished. In addition, the ability of SRIF to inhibit AII-stimulated steroid production was markedly reduced by PT treatment. The binding of [125I]AII to high affinity sites in intact cells and particulate fractions, and modulation of the binding by guanine nucleotides, were unaffected by toxin pretreatment, even under conditions where a 40-41K protein was completely ADP ribosylated. In contrast, the toxin substantially diminished the binding of [125I]Tyr0-SRIF to SRIF receptors in glomerulosa cells (by 50% after 5 h and by 90% after 20 h). These results indicate that Ni or a similar protein probably mediates the inhibition of cAMP formation by AII and the attenuation of the steroid response by high concentrations of AII as well as the inhibitory actions of SRIF in the adrenal glomerulosa cell. Furthermore, the lack of effect of PT on AII binding and stimulation of GTPase activity suggests the existence of an additional pertussis-insensitive guanine nucleotide-regulatory protein that is activated by lower concentrations of AII and mediates the stimulation of aldosterone production.
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PMID:Control of aldosterone production by angiotensin II is mediated by two guanine nucleotide regulatory proteins. 288 77

Utilizing a proteoliposome reconstitution system, we have purified the rat liver V1 vasopressin receptor to near homogeneity. The receptor was purified approximately 21,000-fold from rat liver membranes, using differential detergent solubilization, size exclusion gel filtration, lectin affinity, and ion-exchange chromatography. The purified receptor exhibits a Kd of 6 nM, when, prior to solubilization, the membranes were exposed to 1 microM vasopressin. This resulted in the association of a pertussis toxin-insensitive guanine nucleotide-binding protein with the receptor during most of the purification procedure. In the absence of this association, the receptor had a Kd of approximately 30 nM. Association of the receptor with a G-protein was confirmed by the ability of vasopressin to stimulate the hydrolysis of [gamma-32P]GTP. The specific activity of the vasopressin-stimulated hydrolysis was 25 nmol/min/mg, approximately 8,000-fold higher than values obtained with crude reconstituted receptor preparations. Cross-linking of 125I-vasopressin to a partially purified preparation of receptor demonstrated that the receptor had a molecular weight of approximately 68,000 under reducing conditions, and 58,000 under nonreducing conditions. The purification procedure may prove useful in purifying a number of small peptide hormone receptors (e.g. bradykinin, angiotensin II) and perhaps their associated G-proteins as well.
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PMID:Purification and characterization of the rat liver vasopressin (V1) receptor. 295 56

Angiotensin II can inhibit glucagon-stimulated cyclic AMP production in hepatocytes and adenylate cyclase activity in hepatic membranes. Pertussis toxin, an exotoxin produced by Bordetella pertussis, was used to investigate the role of the inhibitory guanine nucleotide-binding regulatory protein of adenylate cyclase (Ni) in coupling angiotensin receptors to the adenylate cyclase system. An assay was developed using [32P] NAD+ to quantitate the amount of Ni protein in the membrane and the extent of its ADP-ribosylation catalyzed by toxin. The ability of angiotensin to inhibit adenylate cyclase and interact with its receptor was compared with the degree of modification of Ni in membranes prepared from isolated hepatocytes. In control membranes angiotensin II inhibited basal adenylate cyclase by 35%. When all of the Ni molecules in the membrane were ADP-ribosylated, angiotensin did not inhibit adenylate cyclase. However, the attenuation of angiotensin's effect on cyclase was not linearly correlated with the degree of modification of Ni; ADP-ribosylation of greater than 80% of the Ni was required before a reduction of the angiotensin effect was observed. A possible explanation for this finding is an excess of Ni molecules in the membrane (approximately 3.4 pmol/mg of membrane protein) over angiotensin II receptors (approximately 1.2 pmol/mg of membrane protein). 125I-angiotensin bound to sites in the membrane with two affinities. Computer fitting of the binding isotherms yielded parameters of N1 = 279 fmol/mg protein, Kd1 = 0.2 nM; N2 = 904 fmol/mg protein, Kd2 = 1.4 nM. When all of the Ni molecules in the membrane were ADP-ribosylated, angiotensin bound to only one site with binding parameters of N = 349 fmol/mg protein, Kd = 0.4 nM. GTP-gamma-S caused a 7-fold increase in the Kd of this site to 2.7 nM. Overall, the data indicate that the Ni protein mediates the effect of angiotensin on adenylate cyclase. The observation that GTP-gamma-S can markedly decrease the affinity of angiotensin receptors when all Ni molecules are ADP-ribosylated suggests that angiotensin receptors may couple to other GTP-binding proteins which may mediate the effects of angiotensin in other signal transduction systems.
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PMID:Role of Ni in coupling angiotensin receptors to inhibition of adenylate cyclase in hepatocytes. 299 49

Despite their opposite effects on prolactin secretion, both dopamine and angiotensin II inhibit adenylate cyclase activity in homogenates of anterior pituitary cells in primary culture. Dopamine and angiotensin II inhibition of adenylate cyclase was not additive, suggesting that both neurohormones inhibit the adenylate cyclase of the lactotroph cells. Pretreatment with Bordetella pertussis toxin (islet activator protein) completely suppressed the dopamine-induced inhibition of both adenylate cyclase and prolactin secretion. The islet activator protein also reversed the angiotensin II-induced inhibition of the adenylate cyclase activity. In contrast, angiotensin II stimulation of prolactin release was not affected by the toxin. Angiotensin II also induced a dose-dependent stimulation of inositol phosphates (250%) with an EC50 of 0.1 nM, close to that observed for prolactin secretion. Islet activator protein pretreatment did not block the stimulation of inositol phosphate production. Dopamine inhibited the angiotensin II-stimulated prolactin release and the production of inositol phosphates induced by angiotensin II. It is concluded that angiotensin II and dopamine receptors of lactotroph cells are able to modulate both cAMP and inositol phosphate production. The dopamine receptor of lactotrophs appears to be the first example of a receptor which is negatively coupled to the production of inositol phosphates.
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PMID:Angiotensin II and dopamine modulate both cAMP and inositol phosphate productions in anterior pituitary cells. Involvement in prolactin secretion. 300 16

Islet-activating protein (IAP, a Bordetella pertussis toxin) was employed to test the hypothesis that the inhibitory GTP-binding regulatory protein of adenylate cyclase (Ni) mediates GTP effects on the binding of Ca2+-mobilizing hormones to liver plasma membranes and is involved in calcium mobilization stimulated by these agonists. IAP added to normal liver plasma membranes catalyzed the incorporation of radioactivity from [32P]NAD into a 41,000-Da peptide (presumably the alpha-subunit of Ni). However, no such incorporation was observed in liver membranes prepared from rats 24 hr after intraperitoneal injection of IAP. Angiotensin II attenuated glucagon-stimulated increases in cAMP in hepatocytes prepared from control but not IAP-treated rats. In contrast, following IAP treatment, no changes were observed in the ability of glucagon, vasopressin, angiotensin II, or epinephrine to activate phosphorylase; nor did this treatment alter [3H]vasopressin binding or epinephrine displacement of [3H]prazosin binding. However, IAP treatment decreased [3H]angiotensin II binding affinity when studies were performed in the absence but not the presence of 5'-guanylylimidodiphosphate (GppNHp). This shift was small and represented only 5-8% of the shift in apparent Kd elicited by GppNHp in untreated membranes. In vitro studies with IAP confirmed the results of the radioligand binding studies using in vivo IAP treatment. The effects of NaCl on [3H]angiotensin II binding were also tested but were not typical of other receptors which couple to Ni. The data suggest that, although a small population of hepatic angiotensin II receptors couple to Ni and attenuate glucagon-stimulated increases in cAMP, vasopressin, alpha 1-adrenergic, and the majority of angiotensin II receptors do not interact significantly with Ni. Thus, although there is evidence that agonist-induced Ca2+ mobilization requires a GTP-binding regulatory protein, this protein does not appear to be Ni in rat liver.
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PMID:Effect of islet-activating pertussis toxin on the binding characteristics of Ca2+-mobilizing hormones and on agonist activation of phosphorylase in hepatocytes. 300 28

Incubation of rat renal mesangial cells with angiotensin II (0.1 microM) resulted in transient breakdown of phosphatidylinositol 4,5-bisphosphate, rapid generation of diacylglycerol and phosphatidic acid, increased 45Ca2+ influx, increased intracellular [Ca2+] as measured by quin 2, and increased prostaglandin E2 synthesis. All of these processes were markedly inhibited time- and dose-dependently by prior exposure of cells to pertussis toxin. In contrast, the effects of the ionophore A23187 on 45Ca2+ influx and prostaglandin E2 synthesis were not altered by the exposure of the cells to pertussis toxin. The action of the toxin was not associated with alterations in cellular concentrations of cyclic AMP. Incubation of membrane fraction of mesangial cells with pertussis toxin resulted in ADP-ribosylation of Mr-42,000 protein. From all these results, it is likely that a G protein is involved in receptor-mediated signal transduction in renal mesangial cells.
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PMID:Pertussis toxin abolishes angiotensin II-induced phosphoinositide hydrolysis and prostaglandin synthesis in rat renal mesangial cells. 302 20

Exposure of bovine adrenocortical cells to optimal concentrations of angiotensin II (A II) resulted in an almost 2-fold enhancement of cellular cAMP accumulation in response to steroidogenic concentrations of ACTH. This effect was dose-dependent and transient, with a maximum after 4-6 min of treatment with A II. Activators of protein kinase C such as 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and 1,2-dioctanoyl-sn-glycerol mimicked that effect in a sustained fashion. The ACTH-sensitized state of the adrenocortical adenylate cyclase system induced by TPA exhibited also an enhanced response to forskolin. On the other hand, previous treatment of the cells by pertussis toxin suppressed any further effect of TPA. It is suggested that, following A II exposure, the Gi inhibitory components of the adrenocortical cell adenylate cyclase system may be inactivated, leading to increased response to ACTH. This process may involve protein kinase C activation, subsequent to intracellular generation of lipidic messengers resulting from accelerated phosphoinositide breakdown induced by angiotensin.
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PMID:Sensitization of adrenocortical cell adenylate cyclase activity to ACTH by angiotensin II and activators of protein kinase C. 303 95


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