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)

We have reported recently that prostaglandin E2 (PGE2) stimulated phosphoinositide metabolism in bovine adrenal chromaffin cells and that PGE2 and ouabain, an inhibitor of Na+, K(+)-ATPase, synergistically induced a gradual secretion of catecholamines from the cells. Here we examined the involvement of a GTP-binding protein(s) in PGE receptor-induced responses by using NaF. In the presence of Ca2+ in the medium, NaF stimulated the formation of all three inositol phosphates, i.e., inositol monophosphate, bisphosphate, and trisphosphate, linearly over 30 min in a dose-dependent manner (15-30 mM). This effect on phosphoinositide metabolism was accompanied by an increase in cytosolic free Ca2+. NaF also induced catecholamine release from chromaffin cells, and the dependency of stimulation of the release on NaF concentration was well correlated with those of NaF-enhanced inositol phosphate formation and increase in cytosolic free Ca2+. Although the effect of NaF on PGE2-induced catecholamine release in the presence of ouabain was additive at concentrations below 20 mM, there was no additive effect at 25 mM NaF. Furthermore, the time course of catecholamine release stimulated by 20 mM NaF in the presence of ouabain was quite similar to that by 1 microM PGE2, and both stimulations were markedly inhibited by amiloride, with half-maximal inhibition at 10 microM. Pretreatment of the cells with pertussis toxin did not prevent, but rather enhanced, PGE2-induced catecholamine release over the range of concentrations examined. These results demonstrate that NaF mimics the effect of PGE2 on catecholamine release from chromaffin cells and suggest that PGE2-evoked catecholamine release may be mediated by the stimulation of phosphoinositide metabolism through a putative GTP-binding protein insensitive to pertussis toxin.
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PMID:Sodium fluoride mimics the effect of prostaglandin E2 on catecholamine release from bovine adrenal chromaffin cells. 189 68

The guanine nucleotide binding proteins (G proteins) that couple hormone and other receptors to a variety of intracellular effector enzymes and ion channels are heterotrimers of alpha, beta, and gamma subunits. One way to study the interfaces between subunits is to analyze the consequences of chemically cross-linking them. We have used 1,6-bismaleimidohexane (BMH), a homobifunctional cross-linking reagent that reacts with sulfhydryl groups, to cross-link alpha to beta subunits of Go and Gi-1. Two cross-linked products are formed from each G protein with apparent molecular masses of 140 and 122 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both bands formed from Go reacted with anti-alpha o and anti-beta antibody. The mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis is anomalous since the undenatured, cross-linked proteins have the same Stokes radius as the native, uncross-linked alpha beta gamma heterotrimer. Therefore, each cross-linked product contains one alpha and one beta subunit. Activation of Go by guanosine 5'-3-O-(thio)triphosphate (GTP gamma S) does not prevent cross-linking of alpha to beta gamma, consistent with an equilibrium between associated and dissociated subunits even in the presence of GTP gamma S. The same cross-linked products of Go are formed in brain membranes reacted with BMH as are formed in solution, indicating that the residues cross-linked by BMH in the pure protein are accessible when Go is membrane bound. Analysis of tryptic peptides formed from the cross-linked products indicates that the alpha subunit is cross-linked to the 26-kDa carboxyl-terminal portion of the beta subunit. The cross-linked G protein is functional, and its alpha subunit can change conformation upon binding GTP gamma S. GTP gamma S stabilizes alpha o to digestion by trypsin (Winslow, J.W., Van Amsterdam, J.R., and Neer, E.J. (1986) J. Biol. Chem. 261, 7571-7579) and also stabilizes the alpha subunit in the cross-linked product. Cross-linked G o can be ADP-ribosylated by pertussis toxin. This ADP-ribosylation is inhibited by GTP gamma S with a concentration dependence that is indistinguishable from that of the control, uncross-linked G o. These two kinds of experiments indicate that alpha o is able to change its conformation even though it cannot separate completely from beta gamma. Thus, although dissociation of the subunits accompanies activation of G o in solution, it is not obligatory for a conformational change to occur in the alpha subunit.
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PMID:Structural and functional studies of cross-linked Go protein subunits. 189 68

Receptors for the chemotactic peptide fMet-Leu-Phe (fMet, N-formylmethionine) are present in membranes of myeloid differentiated human leukemia (HL-60) cells and stimulate phospholipase C via a pertussis-toxin-sensitive guanine-nucleotide-binding regulatory protein(s) [G-protein(s)]. We have developed methods for the assessment of formyl-peptide-receptor-stimulated binding of radiolabeled guanosine 5'-[gamma-thio]triphosphate ([35S]GTP[S]) to native HL-60 membranes. Agonist stimulation of [35S]GTP[S] association with the membrane was minimal (less than or equal to 20%) when GTP[S] was the sole nucleotide present in the incubation medium. In contrast, receptor activation led to a marked (up to sixfold) stimulation of [35S]GTP[S] binding when GDP or GTP were present in high (greater than 100-fold) excess of [35S]GTP[S]. The increase in [35S]GTP[S] binding caused by the chemotactic agonist was strictly dependent on the presence of Mg2+ and was significantly increased by Na+. Agonist-independent binding of [35S]GTP[S] and the increase due to the chemotactic agonist were markedly attenuated by both pertussis and cholera toxin. Comparison of the number of chemotactic-peptide-sensitive [35S]GTP[S]-binding sites to the number of chemotactic peptide receptors present in HL-60 membranes provided direct evidence that a single formyl-peptide receptor is capable of catalyzing the binding of [35S]GTP[S] to, and thus the activation of, multiple (up to 20) G-proteins in native plasma membranes.
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PMID:Signal amplification in HL-60 granulocytes. Evidence that the chemotactic peptide receptor catalytically activates guanine-nucleotide-binding regulatory proteins in native plasma membranes. 190 7

Sodium salicylate and other non-steroidal anti-inflammatory drugs (NSAIDs) inhibit neutrophil functions via unknown mechanisms. To examine their site of action in the neutrophil we have studied discrete events within the plasma membrane which depend upon the normal function of a GTP binding protein (G protein). We demonstrated that sodium salicylate and piroxicam inhibit neutrophil activation in response to stimuli which require signal transduction via a G protein (e.g. formyl-methionine-leucine-phenylalanine) but have no effect on stimuli which do not (e.g. phorbol myristate acetate, ionomycin). NSAIDs blocked the ADP-ribosylation of the pertussis toxin substrate in human neutrophils. This effect was associated with the capacity of NSAIDs to block pertussis toxin-dependent inhibition of neutrophil functions. Finally, NSAIDs inhibited the binding of GTP gamma S, a stable analog of GTP, to purified neutrophil membrane preparations. The data indicate that salicylate and other NSAIDs interact with a G protein in the neutrophil plasmalemma and thereby uncouple post-receptor signaling events.
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PMID:Non-steroidal anti-inflammatory drugs: effects on a GTP binding protein within the neutrophil plasma membrane. 190 24

Following a previous report on detection of muscarinic receptors in myelin with the implied presence of G proteins, we now demonstrate by more direct means the presence of such proteins and their quantification. Using [35S]guanosine 5'-O-(3-thiotriphosphate) ([35S]GTP gamma S) as the binding ligand, purified myelin from bovine brain was found to contain approximately half the binding activity of whole white matter (138 +/- 9 vs. 271 +/- 18 pmol/mg of protein). Scatchard analysis of saturation binding data revealed two slopes, a result suggesting at least two binding populations. This binding was inhibited by GTP and its analog but not by 5'-adenylylimidodiphosphate [App(NH)p], GMP, or UTP. Following sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) of myelin proteins and blotting on nitrocellulose, [alpha-32P]GTP bound to three bands in the 21-27-kDa range in a manner inhibited by GTP and GTP gamma S but not App(NH)p. ADP-ribosylation of myelin with [32P]NAD+ and cholera toxin labeled a protein of 43 kDa, whereas reaction with pertussis toxin labeled two components of 40 kDa. Cholate extract of myelin subjected to chromatography on a column of phenyl-Sepharose gave at least three major peaks of [35S]GTP gamma S binding activity. SDS-PAGE and immunoblot analyses of peak I indicated the presence of Go alpha, Gi alpha, and Gs alpha. Further fractionation of peak II by diethyl-aminoethyl-Sephacel chromatography gave one [35S]GTP gamma S binding peak with the low-molecular-mass (21-27 kDa) proteins and a second showing two major protein bands of 36 and 40 kDa on SDS-PAGE.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection of G proteins in purified bovine brain myelin. 190 10

The A1 adenosine receptor is the best characterized of the widely distributed purinergic receptor family. The purified brain A1 receptor is a monomeric 35- to 36-kDa glycoprotein. A1 receptors can be clearly distinguished from A2 adenosine receptors on the basis of structure activity relationships with selective ligands. Recent structure activity data suggest that subtypes of A1 (A1a, A1b, and A3) and A2 (A2a and A2b) receptors may exist. A1 receptor-mediated responses are coupled via multiple pertussis toxin-sensitive GTP binding proteins (G proteins) to many different effectors in various tissues: adenylate cyclase, phospholipase C, Na+- Ca2+ exchange, Ca2+ channels, Cl- channels, and K+ channels. The formation of calcium-mobilizing inositol phosphates can either be enhanced or inhibited. In general, adenosine has been found to act in concert with other hormones or neurotransmitters in either an inhibitory or a stimulatory way. The myriad modulatory actions of adenosine suggest that: 1) adenosine may simultaneously produce multiple effects within the same cell; and 2) activation of A1 receptors may lead to either a decrease or an increase in the coupling of other receptors to their G proteins.
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PMID:Structure and function of A1 adenosine receptors. 191 91

The vascular tree and the mesangium in the glomerulus respond to various hormones, growth factors, and autonomic signals, leading to generation of second messengers and regulation of ion channels. Guanine nucleotide regulatory proteins (G proteins) mediate these effects in other systems. Glomerular G proteins were studied by immunoblotting and immunohistochemical techniques. Glomeruli were isolated from bovine kidney cortex by differential sieving. Glomerular proteins were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and nitrocellulose transfers were immunoblotted with antibodies to G proteins. G alpha,common antiserum (P-960) recognized proteins with a molecular mass of 41 to 45 kDa. Antibodies against peptide sequences specific to Gi alpha and Go alpha demonstrated Gi alpha, 1/3 (molecular mass, 39 to 41 kDa), Gi alpha 2 (molecular mass, 40 kDa), and Go alpha (molecular mass, 39 kDa). Presence of these proteins was further confirmed by pertussis toxin-catalyzed ADP ribosylation of protein(s) with a molecular mass of 39 to 41 kDa in the glomeruli. Immunohistochemical staining of frozen sections from bovine kidney cortex revealed the presence of Gi alpha 2 in capillary loop distribution in glomeruli and interstitium, but Gi,1/3 or Go could not be demonstrated. The pattern of immunofluorescence with Gi alpha 2 antiserum suggested localization of Gi alpha 2 to the endothelium in glomerular and interstitial vasculature. The novel finding of Go in glomeruli requires localization of Go to specific cells and determination of its role in glomerular physiology. In conclusion, these studies demonstrate that bovine kidney glomeruli express alpha subunits of pertussis toxin-sensitive GTP-binding proteins Gi,1/3, Gi,2 and Go.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification and localization of pertussis toxin-sensitive GTP-binding proteins in bovine kidney glomeruli. 195 30

The first step in net active transepithelial transport of sodium in tight epithelia is mediated by the amiloride-blockable sodium channel in the apical membrane. This sodium channel is the primary site for discretionary control of total body sodium and, therefore, investigating its regulatory mechanisms is important to our understanding of the physiology of fluid and electrolyte balance. Because essentially all of the regulatory sites on the channel are on the intracellular surface, patch clamp methods have proven extremely useful in the electrophysiological characterization of the sodium channel by isolating it from other channel proteins in the epithelial membrane and by allowing access to the intracellular surface of the protein. We have examined three different regulatory mechanisms. (1) Inhibition of channel activity by activation of protein kinase C; (2) activation of the channel by agents which activate G-proteins; and (3) modulation of channel kinetics and channel number by mineralocorticoids. Activation of protein kinase C by phorbol esters or synthetic diacylglycerols reduces the open probability of sodium channels. Protein kinase C can be activated in a physiological context by enhancing apical sodium entry. Actions which reduce sodium entry (low luminal sodium concentrations or the apical application of amiloride) increase channel open probability. The link between sodium entry and activation of protein kinase C appears to be mediated by intracellular calcium activity linked to sodium via a sodium/calcium exchange system. Thus, the intracellular sodium concentration is coupled to sodium entry in a negative feedback loop which promotes constant total entry of sodium. Activation of G-proteins by pertussis toxin greatly increases the open probability of sodium channels. Since channels can also be activated by pertussis toxin or GTP gamma S in excised patches, the G-protein appears to be closely linked in the apical membrane to the sodium channel protein itself. The mechanism for activation of this apical G-protein, when most hormonal and transmitter receptors are physically located on the basolateral membrane, is unclear. Mineralocorticoids such as aldosterone have at least two distinct effects. First, as expected, increasing levels of aldosterone increase the density of functional channels detectable in the apical membrane. Second, contrary to expectations, application of aldosterone increases the open probability of sodium channels. Thus aldosterone promotes the functional appearance of new sodium channels and promotes increased sodium entry through both new and pre-existant channels.
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PMID:Regulation of the amiloride-blockable sodium channel from epithelial tissue. 196 46

Islet-activating protein (IAP), one of the pertussis toxins, serving [alpha-32P]nicotinamide adenine dinucleotide (NAD) as a substrate for ADP ribosylation, radiolabelled a specific pig epidermal membrane protein. The IAP-specific substrate was detectable by sodium dodecyl sulphate-polyacrylamide gel electrophoresis as a single band corresponding to a molecular weight of 40 kDa. The ADP ribosylation catalysed by IAP was inhibited by the addition of Mg2+ to the reaction mixture. IAP is known to work on intact cell systems resulting in the ADP ribosylation using intracellular NAD as the ADP ribose donor. Following IAP pretreatment of intact pig epidermis, the epidermal receptor adenylate cyclase responses were markedly increased; all the stimulatory receptor adenylate cyclase responses (beta-adrenergic, prostaglandin E, adenosine and histamine responses) were significantly increased. Cholera toxin-induced cyclic AMP accumulation was also significantly increased. Forskolin-induced cyclic AMP accumulation was slightly increased after IAP pretreatment, but this was not statistically significant. The IAP-dependent ADP ribosylation of the epidermal 40 kDa membrane protein, which was prepared from the IAP pretreated epidermis, was significantly decreased. It is known that the tumour promoter, phorbol 12-myristate,13-acetate (PMA), decreases stimulatory receptor adenylate cyclase responses of the epidermis. Following the PMA pretreatment, IAP-dependent ADP ribosylation of the epidermal membrane protein was unaffected. Furthermore, following the PMA pretreatment, the IAP-induced increase in the epidermal receptor adenylate cyclase responses still remained. Our results indicate that pig epidermis contains 40 kDa membrane substrate for IAP-dependent ADP ribosylation, which has an inhibitory tonus on the epidermal adenylate cyclase until its ADP ribosylation by IAP.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibitory guanine nucleotide binding protein in pig epidermis: regulation of epidermal adenylate cyclase. 196 35

Signal transduction for the characteristic long-term desensitization of glutamate receptors in Purkinje cells was investigated with wedge recordings from rat cerebellar slices. Long-term desensitization was induced specifically in the AMPA-selective subtype of glutamate receptors following brief exposure to 100 microM quisqualate. It was abolished either by treatment of the rat with pertussis toxin or by perfusion of a slice with BAPTA-AM, L-NMMA, hemoglobin, or inhibitor of PKG. Brief application of AMPA alone did not cause desensitization, but in combination with t-ACPD, sodium nitroprusside, or 8-bromo-cGMP, AMPA produced desensitization similar to that induced by quisqualate. These results indicate that the desensitization arises from activation of AMPA receptors in association with activation of metabotropic glutamate receptors, the latter leading to Ca2+ elevation to nitric oxide (NO) production to cGMP synthesis, and eventually to activation of PKG.
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PMID:Messengers mediating long-term desensitization in cerebellar Purkinje cells. 196 3


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