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)

Whole-cell patch-clamp recordings were obtained from light-responsive on-bipolar cells in retinal slices of the dogfish. Inclusion of the A-subunit of pertussis toxin in the patch-pipette solution resulted in an increase in inward current and membrane conductance, and a block of light-evoked currents of on-bipolar cells. The opposite effect was obtained with the A-subunit of cholera toxin, which blocked light responses, and induced an outward current and a decrease in membrane conductance. These actions were NAD+ dependent. The results show that the G-protein(s) linking glutamate receptors to a cGMP cascade in on-bipolar cells possess sites which are ADP-ribosylated by pertussis and cholera toxins, with no homology to the adenylate cyclase system but possibly with a homology to transducin. Furthermore, inclusion of H-7, a kinase inhibitor in the patch-pipette solution, or of a non-hydrolysable ATP analogue (AMP-PNP) had no effect on light responses, membrane conductance or dark current of on-bipolar cells, suggesting that the components of this cGMP cascade are unlikely to be regulated by protein kinases.
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PMID:The glutamate-receptor linked cGMP cascade of retinal on-bipolar cells is pertussis and cholera toxin-sensitive. 134 16

In enzymatically dispersed enriched rat parietal cells we studied the effect of pertussis toxin on prostaglandin E2 (PGE2)- or somatostatin-induced inhibition of H(+)-production. Parietal cells were incubated in parallel in the absence (control cells) and presence of pertussis toxin (250 ng/ml; 4 h). [14C]Aminopyrine accumulation by both pertussis toxin-treated and control cells was used as an indirect measure of H(+)-production after stimulation with either histamine, forskolin or dibutyryl adenosine 3',5'-cyclic monophosphate (dbcAMP) alone and in the presence of PGE2 (10(-9)-10(-7) M) or somatostatin (10(-9)-10(-6) M). PGE2 inhibited histamine- and forskolin-stimulated [14C]aminopyrine accumulation but failed to alter the response to dbcAMP. Somatostatin was less effective and less potent than PGE2 in inhibiting stimulation by histamine or forskolin and reduced the response to dbcAMP. Pertussis toxin completely reversed inhibition by both PGE2 and somatostatin on histamine- and forskolin-stimulated H(+)-production but failed to affect inhibition by somatostatin of the response to dbcAMP. After incubation of crude control cell membranes with [32P]NAD+, pertussis toxin catalysed the incorporation of [32P]adenosine diphosphate (ADP)-ribose into a membrane protein of molecular weight of 41,000, the known molecular weight of the inhibitory subunit of adenylate cyclase (Gi alpha). Pertussis toxin treatment of parietal cells prior to the preparation of crude membranes almost completely prevented subsequent pertussis toxin-catalysed [32P]ADP ribosylation of the 41,000 molecular weight protein.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pertussis toxin reverses prostaglandin E2- and somatostatin-induced inhibition of rat parietal cell H(+)-production. 135 83

A guanosine 5'-[gamma-[35S]thio]triphosphate-binding activity was detergent-extracted from Trypanosoma cruzi membranes. This binding activity was co-eluted from gel-filtration columns with a factor which, in a heterologous reconstitution system, blocks glucagon stimulation of adenylate cyclase activity in liver membranes. ADP-ribosylation of these membranes by pertussis toxin eliminated this blocking capacity. Incubation of T. cruzi membranes with activated pertussis toxin and [adenylate-32P]NAD+ led to the incorporation of radioactivity into a labelled product with an apparent M(r) of approx. 43,000. Crude membranes were electrophoresed on SDS/polyacrylamide gels and analysed, by Western blotting, with GA/1 anti-alpha common, AS/7 anti-alpha t, anti-alpha i1 and anti-alpha i2 polyclonal antibodies. These procedures led to the identification of a specific polypeptide band of about 43 kDa. Another polypeptide reacting with the SW/1 anti-beta antibody, of about 30 kDa, was also detected in the membrane fraction.
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PMID:Characterization of a Gi-protein from Trypanosoma cruzi epimastigote membranes. 144 3

We have previously shown that the stimulatory effects of guanine nucleotides, N-ethylcarboxamide-adenosine and other agonists on adenylate cyclase activity were diminished in aorta and heart sarcolemma of spontaneously hypertensive rats (SHR) [Anand-Srivastava (1988) Biochem. Pharmacol. 37, 3017-3022]. In the present studies, we have examined whether the decreased response of these agonists is due to the defective GTP-binding proteins (G-proteins) which couple the receptors to adenylate cyclase, and have therefore measured the levels of G-proteins in aorta and heart from SHR and their respective Wistar-Kyoto (WKY) controls by using pertussis toxin (PT)- and cholera toxin (CT)-catalysed ADP-ribosylations and immunoblotting techniques using specific antibodies against G-proteins. The labelling with [32P]NAD+ and PT identified a 40/41 kDa protein in heart and aorta from WKY and SHR and was significantly increased in the hearts (approximately 100%) and aorta (approximately 30-40%), from SHR as compared with WKY. Immunoblotting revealed an increase in the levels of the G-protein alpha-subunits Gi alpha-2 and Gi alpha-3 in heart and Gi alpha-2 in aorta, whereas no change in Go alpha was observed in heart from SHR and WKY. On the other hand, no differences were observed in CT labelling or immunoblotting of stimulatory G-protein (Gs) in heart and aorta from WKY and SHR. In addition, CT stimulated the adenylate cyclase activity in heart sarcolemma from WKY and SHR to a similar extent. These results were correlated with adenylate cyclase inhibition and stimulation by various hormones. Angiotensin II (AII), atrial natriuretic factor (ANF) and oxotremorine-mediated inhibition was found to be greater in SHR as compared with WKY, whereas the stimulatory effects of adrenaline, isoprenaline, dopamine and forskolin were diminished in SHR aorta as compared to WKY. These results indicate that regulatory protein G(i) is more expressed in SHR, which may be associated with the decreased responsiveness of stimulatory hormones and increased sensitivity of inhibitory hormones to stimulate/inhibit adenylate cyclase activity. It may thus be suggested that the enhanced G(i) activity may be one of the mechanisms responsible for the diminished vascular tone and impaired myocardial functions in hypertension.
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PMID:Enhanced expression of inhibitory guanine nucleotide regulatory protein in spontaneously hypertensive rats. Relationship to adenylate cyclase inhibition. 144 83

The GTP-binding proteins on luminal and basolateral membrane vesicles from outer cortex (pars convoluta) and outer medulla (pars recta) of rabbit proximal tubule have been examined. The membrane vesicles were highly purified, as ascertained by electron microscopy, by measurements of marker enzymes, and by investigating segmental-specific transport systems. The [35S]GTP gamma S binding to vesicles, and to sodium cholate-extracted proteins from vesicles, indicated that the total content of GTP-binding proteins were equally distributed on pars convoluta, pars recta luminal and basolateral membranes. The membranes were ADP-ribosylated with [32P]NAD+ in the presence of pertussis toxin and cholera toxin. Gel electrophoresis revealed, for all preparations, the presence of cholera toxin [32P]ADP-ribosylated 42 and 45 kDa G alpha s proteins, and pertussis toxin [32P]ADP-ribosylated 41 kDa G alpha i1, 40 kDa G alpha i2 and 41 kDa G alpha i3 proteins. The 2D electrophoresis indicated that Go's were not present in luminal nor in basolateral membranes of pars convoluta or pars recta of rabbit proximal tubule.
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PMID:GTP-binding proteins in luminal and basolateral membranes from pars convoluta and pars recta of rabbit kidney proximal tubule. 161 19

The equilibrium dissociation constant of NAD+ and pertussis toxin was determined by equilibrium dialysis and by the quenching of the protein's intrinsic fluorescence on titration with NAD+. A binding constant, Kd, of 24 +/- 2 microM at 30 degrees C was obtained from equilibrium dialysis, consistent with the previously determined value for the Michaelis constant, Km, of 30 +/- 5 microM for NAD+ (when the toxin is catalysing the ADP-ribosylation of water and of dithiothreitol). The intrinsic fluorescence of pertussis toxin was quenched by up to 60% on titration with NAD+, and after correction for dilution and inner filter effects, a Kd value of 27 microM at 30 degrees C was obtained, agreeing well with that found by equilibrium dialysis. The binding constants were measured at a number of temperatures using both techniques, and from this the enthalpy of binding of NAD+ to toxin was determined to be 30 kJ.mol-1, a typical value for a protein-ligand interaction. There is one binding site for NAD+ per toxin molecule.
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PMID:Binding of NAD+ to pertussis toxin. 164 4

Treatment of rat hepatocytes with epidermal growth factor (EGF) produced an enhanced tyrosine phosphorylation of the EGF receptor and phospholipase C-gamma (PLC-gamma) in conjunction with the mobilization of Ca2+. Approximately 30% of the total PLC-gamma was tyrosine-phosphorylated with a maximum being reached after 30 s of incubation with EGF. Pretreatment of the rats with pertussis toxin prior to isolation of the hepatocytes blocked EGF-induced tyrosine phosphorylation of PLC-gamma and Ca2+ mobilization but had no effect on autophosphorylation of the EGF receptor or Ca2+ responses elicited by angiotensin II or phenylephrine. Under these conditions Gi protein alpha subunits were fully ADP-ribosylated. A 41-kDa Gi protein alpha subunit was found to be present in the anti-PLC-gamma immune complex after EGF stimulation as shown by in vitro ADP-ribosylation using [32P]NAD+ and activated pertussis toxin. The kinetics of association between PLC-gamma with Gi alpha protein reached a maximum after 1 min of incubation with EGF. Antibodies specific for the EGF receptor also coimmunoprecipitated a Gi protein alpha subunit. Treatment of hepatocytes with EGF caused first an increase and then a decrease in the amount of Gi protein alpha subunit associated with the EGF receptor. In contrast, studies with cultured rat liver (WB) cells, a cell line in which EGF stimulation of phosphoinositide hydrolysis is not inhibited by pertussis toxin, showed that a stable complex of Gi alpha was not formed with either PLC-gamma or EGF receptor immunoprecipitates. These results indicate that a pertussis toxin-sensitive Gi protein is uniquely involved in the signal transduction pathway mediating EGF-induced activation of PLC-gamma and Ca2+ mobilization in hepatocytes.
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PMID:Pertussis toxin-sensitive Gi protein involvement in epidermal growth factor-induced activation of phospholipase C-gamma in rat hepatocytes. 165 96

Transducin, the signal coupling protein of retinal rod photoreceptor cells, is one of a family of G proteins that can be inactivated by pertussis toxin. We have investigated the nature of this inactivation in order to determine (1) whether it requires the toxin-catalyzed transfer of ADP-ribose from NAD+ to cysteine-347 of the alpha subunit and (2) whether it involves locking the alpha subunit in the inactive conformation characteristic of its GDP-bound state, or is limited to disruption of binding to photoexcited rhodopsin (R*). Our results indicate that all observed effects of pertussis toxin treatment, including a shift in the electrophoretic mobility of transducin's alpha subunit and functional inactivation, require NAD+ and that the appearance of the shift parallels incorporation of ADP-ribose. We have also found that, apart from interactions with photoexcited rhodopsin, the functional properties of ADP-ribosylated transducin are essentially the same as those of unmodified transducin. Normal spontaneous nucleotide exchange kinetics and the ability to activate cGMP phosphodiesterase are preserved following quantitative ADP-ribosylation, as are the abilities to hydrolyze GTP, to bind to a dye affinity column, and to display enhanced fluorescence upon addition of Al3+ and F-. Thus, ADP-ribosylation merely blocks catalysis of transducin nucleotide exchange by R* and does not lock transducin in an inactive state.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Nucleotide exchange and cGMP phosphodiesterase activation by pertussis toxin inactivated transducin. 166 Nov 43

Bovine brain microtubule protein, containing both tubulin and microtubule-associated proteins, undergoes ADP-ribosylation in the presence of [14C]NAD+ and a turkey erythrocyte mono-ADP-ribosyltransferase in vitro. The modification reaction could be demonstrated in crude brain tissue extracts where selective ADP-ribosylation of both the alpha and beta chains of tubulin and of the high molecular weight microtubule-associated protein MAP-2 occurred. In experiments with purified microtubule protein, tubulin dimer, the high molecular weight microtubule-associated protein MAP-2, and another high molecular weight mirotubule-associated protein which may be a MAP-1 species were heavily labeled. Tubulin and MAP-2 incorporated [14C]ADP-ribose to an average extent of approximately 2.4 and 30 mol of ADP-ribose/mol of protein, respectively. Assembly of microtubule protein into microtubules in vitro was inhibited by ADP-ribosylation, and incubation of assembled steady-state microtubules with ADP-ribosyltransferase and NAD+ resulted in rapid depolymerization of the microtubules. Thus, the eukaryotic enzyme can ADP-ribosylate tubulin and microtubule-associated proteins to much greater extents than previously observed with cholera and pertussis toxins, and the modification can significantly modulate microtubule assembly and disassembly.
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PMID:Microtubule protein ADP-ribosylation in vitro leads to assembly inhibition and rapid depolymerization. 173 82

Systemic infusion of angiotensin II, a potent agonist, using doses that are initially subpressor, eventually produces sustained blood pressure elevation and reductions in glomerular capillary ultrafiltration coefficient characterized by enhanced signal transduction to angiotensin II and other agonists. In this setting, there is a significant increased affinity of angiotensin II binding to smooth muscle and glomerular mesangial receptors and enhanced sensitivity and magnitude of angiotensin II-induced decrements in cyclic AMP. Since G proteins are important modulators of binding and signal transduction, the present studies were designed to test the hypothesis that differences in the relative amounts of G proteins may be present and have accounted for differences observed. G proteins were identified and quantitated by isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis, radiolabeling in the presence of activated toxins with [gamma-32P]NAD+, immunoprecipitation, and immunoblotting. A 168% and 465% increase in pertussis toxin-catalyzed ADP ribosylation of alpha 40-41 was found in angiotensin II-treated groups over control groups for glomerular and mesenteric membranes, respectively. Immunoblotting revealed a 250% and 35% increase in the levels of the Gi isoforms alpha i-2 and alpha i-3, respectively, and a decrease of 53% in alpha i-1 from the angiotensin II-treated group. No differences were observed in cholera toxin labeling or immunoblotting of Gs. These results demonstrate multiple mechanisms whereby angiotensin-induced signal transduction can be modulated involving both the receptors and G proteins. These observed differences in G proteins in systemic and renal vasculature accompanying angiotensin II infusion suggest the possibility of a regulatory role in the pathophysiology of angiotensin II-induced hypertension and renal disease.
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PMID:Angiotensin II-induced changes in guanine nucleotide binding and regulatory proteins. 173 48


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