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Query: UMLS:C0043167 (
pertussis
)
19,595
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Vasoactive intestinal peptide (VIP) evokes little or no secretion of catecholamines from cultured bovine chromaffin cells. However, pretreatment of chromaffin cells with
pertussis
toxin (PTX, 100 ng/ml for > or = 4 h) revealed that VIP is a secretagogue. In PTX-treated cells catecholamine secretion evoked by VIP occurs with minimal elevation of cyclic AMP and is only slightly enhanced by cyclic nucleotide phosphodiesterase inhibitors. Forskolin, a direct activator of adenylate cyclase, causes delayed secretion of catecholamines from chromaffin cells treated with PTX, but only with pronounced elevation of cyclic AMP levels. Stimulation of catecholamine secretion by histamine, known to activate
phosphatidylinositol-specific
phospholipase C in chromaffin cells, is also enhanced by preincubation of the cells with PTX. These results suggest that in the bovine chromaffin cell a PTX-sensitive G-protein mediates tonic inhibition of secretion, possibly by preventing activation of phospholipase C.
...
PMID:Vasoactive intestinal peptide is a secretagogue in bovine chromaffin cells pretreated with pertussis toxin. 133 35
Studies on the role of microtubule integrity in stimulus-response coupling in neutrophils have generated contradictory data. To determine the role of microtubule integrity in stimulus-response coupling elicited by two different mechanisms, i.e., engagement of the Fc receptors (FcR gamma II, FcR gamma III) or engagement of the receptor for FMLP, we utilized colchicine (10 microM), which reduces pericentriolar microtubules to 29% of control, and compared its effect with that of nocodazole (50 microM) and lumicolchicine (10 microM). We now demonstrate that treatment of neutrophils with colchicine but not lumicolchicine, inhibits degranulation elicited by engagement of Fc receptors but augments degranulation in response to FMLP. In contrast to the ligand-specific effect of microtubule-disruption on degranulation, superoxide anion production (assembly of the NADPH oxidase) is unaffected by colchicine regardless of the ligand. To determine whether intact microtubules were required for responses elicited by ligation of Fc gamma RII(CD32) or Fc gamma RIII(CD16), mAb directed against these receptors were employed. Treatment of neutrophils with mAb KuFc79 directed against Fc gamma RII(CD32) or mAb 3G8 directed against Fc gamma RIII(CD16) inhibited degranulation of neutrophils elicited by immune complexes (IC). In contrast, removal of most of Fc gamma RIII by
phosphatidylinositol-specific
phospholipase C did not significantly alter degranulation in response to IC. We conclude that degranulation elicited by IC results from ligation of both Fc gamma RII and
phosphatidylinositol-specific
phospholipase C-insensitive Fc gamma RIII. The importance of microtubule integrity on the generation of intracellular signals was also examined. Degranulation of neutrophils proceeds via
pertussis
toxin-sensitive and insensitive pathways; treatment of cells with colchicine did not augment the action of
pertussis
toxin. Stimulation of neutrophils by chemoattractants results in a biphasic increase in 1,2-sn-diacylglycerol; a rapid increase ("triggering") secondary to the action of a
phosphatidylinositol-specific
phospholipase C, and a late increase ("activation") secondary to the action of a phosphatidylcholine-specific phospholipase C. Treatment of cells with colchicine altered the production of both [3H]-arachidonic acid-diacylglycerol and diacyl[14C]glycerol in parallel to its effect on degranulation. These studies indicate that the requirement of intact microtubules for degranulation is ligand-specific. Furthermore, assembly of the respiratory burst oxidase does not require intact microtubules. Microtubules most likely alter the cycling of specific receptors or the generation of specific intracellular signals required for stimulus-response coupling in the course of degranulation. Intact microtubules are not uniformly required for the discharge of granule contents during exocytosis.
...
PMID:Differences in signal transduction between Fc gamma receptors (Fc gamma RII, Fc gamma RIII) and FMLP receptors in neutrophils. Effects of colchicine on pertussis toxin sensitivity and diacylglycerol formation. 184 87
Stimulation of the T lymphocyte antigen receptor-CD3 complex (TCR-CD3) causes T cell activation by a process associated with increased
phosphatidylinositol-specific
phospholipase C (PI-PLC) activity. Evidence exists suggesting that GTP-binding (G) proteins, particularly the
pertussis
toxin (PT)-sensitive Gi proteins, participate in this signal transduction pathway. To clarify the role of Gi proteins in TCR-CD3 signaling, and to investigate other possible functions of Gi molecules in T cells, we expressed the S1 subunit of PT in the thymocytes of transgenic mice using the lymphocyte-specific lck promoter. Transgenic thymocytes contained S1 activity and exhibited profound depletion of Gi protein PT substrates in a manner suggesting their inactivation by S1 in vivo. Nevertheless, treatment of transgenic thymocytes with mitogenic stimuli provoked normal increases in intracellular free Ca2+ concentrations and IL-2 secretion, indicating that Gi proteins are not required for T cell activation. These normal signaling responses notwithstanding, mature thymocytes accumulated in lck-PT mice and did not appear in secondary lymphoid organs or in the circulation. Viewed in the context of the known features of Bordetella
pertussis
infection, our results suggest that a PT-sensitive signaling process, probably involving Gi proteins, regulates thymocyte emigration.
...
PMID:Dissection of thymocyte signaling pathways by in vivo expression of pertussis toxin ADP-ribosyltransferase. 212 51
The phosphorylation of the lipocortin-related protein, p68, found in Ca2+-dependent association with the submembranous cytoskeleton has been studied using isolated human placental syncytiotrophoblast plasma membrane vesicles. p68 undergoes rapid, cation-independent phosphorylation in unstimulated membrane vesicles which was inhibited, in a dose-dependent manner, by insulin, platelet-derived growth factor, macrophage colony stimulating factor, protein kinase C-activating phorbol esters and
phosphatidylinositol-specific
phospholipase C. Epidermal growth factor had no effect on overall p68 phosphorylation. Transferrin induced an increase in p68 phosphorylation. However, phosphotyrosine was detected in p68 after treatment with epidermal growth factor, macrophage colony stimulating factor or transferrin, whereas a reduction in p68 phosphorylation appeared to be restricted to serine. cAMP and both cholera and
pertussis
toxins inhibited p68 phosphorylation. Both toxins were synergistic with the effects of insulin and platelet-derived growth factor whilst being antagonistic to the effect of transferrin. Epidermal growth factor and both human and equine immunoglobulin G, all of which alone did not affect overall p68 phosphorylation, reduced cholera or
pertussis
toxin-induced inhibition of p68 phosphorylation. Several phosphatase inhibitors failed to prevent macrophage colony stimulating factor-induced reduction of p68 phosphorylation. These results indicate that (i) p68 is a potential substrate of receptor tyrosyl kinases, (ii) p68 is not phosphorylated by protein kinase C or cAMP-dependent kinase and (iii) p68 phosphorylation is inhibited by activation of multiple pathways including those employing diacylglycerol or cAMP as second messengers.
...
PMID:The phosphorylation of p68, a calcium-binding protein associated with the human syncytiotrophoblast submembranous cytoskeleton, is modulated by growth factors, activators of protein kinase C and cyclic AMP. 255 24
Guinea pig tracheal epithelial cells in primary air/liquid interface culture (GPTE) and virally transformed human bronchial epithelial cells (BEAS-2B) were exposed to histamine at concentrations of 1 to 100 microM. At concentrations greater than 1 microM, histamine elicited a concentration-dependent increase in accumulation of inositol phosphates in both cell types, as assessed by anion exchange chromatography. The effects of histamine were most pronounced at 15 to 30 min and were attenuated by the H1-receptor antagonist, pyrilamine. The H2-receptor antagonist, ranitidine, was without effect. Sodium fluoride (25 mM), a non-receptor-associated activator of GTP binding (G) proteins, increased accumulation of inositol phosphates within GPTE and BEAS cells. In cells permeabilized with digitonin, the nonhydrolyzable GTP analog, guanosine-5'-O-(3-thiotriphosphate) (GTP gamma S; 10 microM) increased inositol phosphate accumulation. This GTP gamma S-induced increase was attenuated by exposure to 500 microM guanosine-5'-O-(2-thiodiphosphate) (GDP beta S). Additionally, histamine-induced increases in inositol phosphate accumulation were potentiated by GTP gamma S and attenuated by GDP beta S. These data indicate involvement of a G protein in the response to histamine. Preincubation with
pertussis
toxin (100 ng/ml for 4 h) did not significantly affect the response, suggesting that the associated G protein was not
pertussis
toxin-sensitive. The presence of the
phosphatidylinositol-specific
phospholipase C (PI-PLC)-associated G protein, G alpha q/11, and the presence of mRNA for the Gq family, were ascertained by immunoblotting and Northern hybridization, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Histamine provokes turnover of inositol phospholipids in guinea pig and human airway epithelial cells via an H1-receptor/G protein-dependent mechanism. 769 21
Bacterial toxin ADP-ribosyltransferases, e.g. diphtheria toxin (DT) and
pertussis
toxin, have in common consensus sequences involved in catalytic activity, which are localized to three regions. Region I is notable for a histidine or arginine; region II, approximately 50-75 amino acids downstream, is rich in aromatic/hydrophobic amino acids; and region III, further downstream, has a glutamate and other acidic amino acids. A similar motif was observed in the sequence of the glycosylphosphatidylinositol-linked muscle ADP-ribosyltransferase. Site-directed mutagenesis was performed to verify the role of this motif. Proteins were expressed in rat adenocarcinoma cells, released from the cell with
phosphatidylinositol-specific
phospholipase C, and quantified with polyclonal antibodies. Transferase His114 in region I aligned with His21 of DT; as with DT, the H114N mutant was active. Aromatic/hydrophobic amino acids (region II) were found approximately 30-50 amino acids downstream of this histidine. Although transferase has a Glu278-Tyr-Ile sequence characteristic of region III in DT, Glu278 was not critical for activity. In an alternative region III containing Glu238-Glu239-Glu240, Glu238 and Glu240 but not Glu239 were critical. Glu240 aligned with critical glutamates in DT, Pseudomonas exotoxin, and C3 transferase. Thus, the mammalian ADP-ribosyltransferases have motifs similar to toxin ADP-ribosyltransferases, suggesting that these sequences are important in ADP-ribose transfer reactions.
...
PMID:Conservation of a common motif in enzymes catalyzing ADP-ribose transfer. Identification of domains in mammalian transferases. 782 77
The coupling of two endothelin receptor subtypes (ET(A) and ETB) to several types of guanine-nucleotide-binding regulatory protein (G protein) was examined. Two subtypes of receptor cDNAs were transfected alone or together with four different G protein alpha subunit cDNAs in COS-7 cells. In ET(A) receptor-transfected cells, endothelin-1 (ET-1) activated
phosphatidylinositol-specific
phospholipase C as measured by the production of phosphatidylinositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. ETB-receptor-transfected cells also produced Ins(1,4,5)P3 on stimulation by ET-1. The ET-1-induced production of Ins(1,4,5)P3 was markedly higher in G alpha q-cotransfected or G alpha 11-cotransfected cells than in cells transfected with each receptor alone. ET-1 also stimulated production of cAMP in ET(A) or ETB receptor-transfected cells. The production of cAMP was synergistically amplified by G alpha s co-transfection with each receptor. In contrast, when G alpha i2 was co-transfected with the ET(A) or ETB receptor, ET-1 displayed an inhibitory action on forskolin-stimulated cAMP accumulation.
Pertussis
-toxin treatment of the G alpha i2-transfected cells resulted in abolition of the endothelin-induced inhibition of cAMP accumulation. These observations indicate that both ET(A) and ETB receptors are able to couple to Gq, G11, Gs and Gi2, and suggest that endothelin receptors stimulate multiple effectors via several types of G protein simultaneously. The overall effects induced by endothelin may differ in cell types depending on the level of expression of each G-protein subtype in the cell.
...
PMID:Molecular identification of guanine-nucleotide-binding regulatory proteins which couple to endothelin receptors. 788 89
Insulin/dexamethasone/methylisobutylxanthine (hormones/IBMX) induce 3T3-L1 fibroblasts to differentiate into adipocytes. Our previous study suggested that
pertussis
toxin (IAP)-sensitive GTP-binding protein(s) (G-protein) is involved in the process of differentiation by hormones/IBMX, accompanied by c-fos induction. Northern blotting indicated that among the IAP-sensitive G-proteins, the levels of Gi2 alpha, Go alpha, and Gi3 alpha mRNA were decreased, increased and unchanged, respectively. Gi1 alpha was undetectable and IAP attenuated the decrease in Gi2 alpha mRNA level but did not affect the change in Go alpha mRNA level during the adipocyte differentiation. These results indicate that IAP-sensitive Gi2 alpha mRNA level is decreased during adipocyte differentiation. A combination of
phosphatidylinositol-specific
phospholipase C (PI-PLC) and IBMX induced c-fos expression in 3T3-L1 fibroblasts similar to that induced with hormones/IBMX. c-fos induced by both stimulators was also diminished by anti-inositolglycan antibody or anti-PI-PLC antiserum. Insulin stimulated the release of inositolproteoglycan and diacylglycerol from 3T3-L1 fibroblasts, which was suppressed by IAP treatment. These findings suggested that one of the pathways of adipocyte differentiation induced by hormones/IBMX occurs via the inositolglycan-specific PI-PLC cascade coupled to IAP-sensitive G-protein(s). Both activation of glycerophosphate dehydrogenase and stimulation of insulin-dependent 2-deoxyglucose uptake induced by hormones/IBMX were enhanced in protein kinase C-depleted cells exposed to phorbol 12-myristate 13-acetate (PMA), and attenuated in IAP-treated cells. The level of a 32P-labeled 52 kDa protein in plasma membrane fractions immunoprecipitated by anti-PI-PLC antiserum was increased by PMA stimulation, abolished in PMA-treated cells, and increased in IAP-treated cells. These findings suggest that protein kinase C phosphorylates PI-PLC, resulting in a decrease in PI-PLC activity related to the signal transduction pathway of adipocyte differentiation of 3T3-L1 fibroblasts.
...
PMID:Possible involvement of phosphatidylinositol-specific phospholipase C related to pertussis toxin-sensitive GTP-binding proteins during adipocyte differentiation of 3T3-L1 fibroblasts: negative regulation of protein kinase C. 798 Dec 46
Acetylcholine (ACh)-induced contraction of esophageal circular smooth muscle cells was inhibited by the M2 muscarinic antagonist methoctramine. In lower esophageal sphincter (LES) cells contraction was inhibited by the M3 antagonist p-fluoro-hexa-hydro-sila-difenidol (pF-HSD).
Pertussis
toxin (PTX) reduced ACh-induced contraction of esophageal but not of LES cells, which suggested that different receptor-linked G proteins are involved. Antibodies against G13 antagonized contraction of esophageal cells and G9-G11 antibodies antagonized contraction of LES cells. The
phosphatidylinositol-specific
phospholipase C (PLC) inhibitors, U-73122 and neomycin, reduced ACh-induced contraction of LES but not of esophageal cells. Conversely, propranolol and p-chloromercuribenzoic acid (pCMB), which inhibit a phosphatidylcholine-specific phospholipase D (PLD)-dependent pathway, reduced contraction of esophageal but not of LES muscle cells. At 1 and 5 sec after the administration of ACh (10(-5) M), inositol 1,4,5-trisphosphate (IP3) increased only in LES muscle, which suggested that contraction results from PLC-induced IP3 production in the LES but not in the esophagus. The IP3 receptor antagonist heparin, and depletion of intracellular Ca++ stores by thapsigargin or A23187, inhibited ACh-induced contraction of LES but not of esophageal muscle. It was concluded that ACh-induced esophageal contraction depends preferentially on M2 receptors, a PTX-sensitive G13 protein, phosphatidylcholine-specific PLD and production of diacylglycerol (DAG) and is independent of IP3 formation and the release of intracellular Ca++. Conversely, LES contraction is mediated through M3 receptors, a PTX-insensitive G9-G11 protein, activation of PLC, IP3 formation and the release of intracellular Ca++.
...
PMID:Distinct muscarinic receptors, G proteins and phospholipases in esophageal and lower esophageal sphincter circular muscle. 826 81
In NG108-15 cells, bradykinin (BK) activates a potassium current (IK,BK) and inhibits the voltage-dependent calcium current (ICa,V). BK also stimulates a
phosphatidylinositol-specific
phospholipase C (PI-PLC). The subsequent release of inositol 1,4,5-trisphosphate and increase in intracellular calcium contribute to IK,BK, through activation of a calcium-dependent potassium current. In membranes from these cells, stimulation of PI-PLC by BK is mediated by Gq and/or G11, two homologous,
pertussis
toxin-insensitive G proteins. Here, we have investigated the role of Gq/11 in the electrical responses to BK. GTP gamma S mimicked and occluded both actions of BK, and both effects were insensitive to
pertussis
toxin. Perfusion of an anti-Gq/11 alpha antibody into the pipette suppressed IK,BK, but not the inhibition of ICa,V by BK. Thus, BK couples to IK,BK via Gq/11, but coupling to ICa,V is most likely via a different, pertussis toxin-insensitive G protein.
...
PMID:Bradykinin modulates potassium and calcium currents in neuroblastoma hybrid cells via different pertussis toxin-insensitive pathways. 829 55
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