UMLS:C0043167 - FACTA Search

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)

GTP stimulation of adenylyl cyclase from the dimorphic pathogenic fungus Candida albicans is greatly enhanced by preincubation of membrane proteins with cholera toxin, NAD and ATP. In the presence of [32P]NAD the toxin catalyzes the covalent incorporation of radioactivity into a membrane protein of 40 kDa. Pertussis toxin catalyzes the transference of the radioactivity from [32P]NAD to a 32 kDa protein. Two major proteins of 40-42 and 30-32 kDa can also be recognized in Western blots by an anti G alpha-common antibody. The results support the idea that G proteins are part of the hormone sensory transduction chain of Candida [(1990) Biochem. Biophys. Res. Commun. 167, 1177-1183].
...
PMID:Enzymatic and immunological detection of G protein alpha-subunits in the pathogenic fungus Candida albicans. 139 91

Previously, we have extensively studied FSH-receptor interactions using bovine calf testis membranes, and demonstrated that the high-affinity FSH binding to receptors and coupling of FSH receptors with guanine nucleotide-binding protein (Gs protein) in a GTP-sensitive state are important initial events in FSH action. In this study, using the same plasma membrane system, we examined the glycoprotein nature of the FSH receptor and determined the contribution of carbohydrate moieties to these functions of the FSH receptor. Our approach involved enzymic deglycosylation of FSH receptors present in calf testis plasma membranes and then removal of incompletely deglycosylated FSH receptors by lectin affinity chromatography. Following treatment of testis membranes with peptide N-glycosidase, the receptor, as identified by ligand-blot analysis, had a higher electrophoretic mobility indicating a decrease in M(r) from 240-200K. Treatment of testis membranes with neuraminidase caused a reduction (to approximately 225K) in the size of the receptor consistent with desialylation. However, digestion with O-glycosidase (endo-alpha-N-acetylgalactosaminidase) did not affect the mobility of the FSH receptor. These results suggest that bovine testis FSH receptor contains predominantly N-linked oligosaccharide chains, a finding which is consistent with recent predictions that N-linked glycosylation, but not O-linked glycosylation sites are present in cloned FSH receptor from rat testis. Moreover, calf testis membranes after treatment with peptide N-glycosidase F, were solubilized with Triton X-100 under optimum conditions that preserve the physical and functional coupling of FSH receptors with guanine nucleotide-binding protein, and then subjected to lectin affinity chromatography. Scatchard analysis indicated that intact and deglycosylated FSH receptors bound 125I-human FSH with similar affinities. In the presence of GTP, the binding of 125I-human FSH to intact and deglycosylated receptors decreased similarly and in a noncompetitive manner. Treatment of testis membranes with NAD plus cholera toxin, but not NAD plus pertussis toxin, eliminated the GTP effect on FSH binding to enzymic deglycosylated as well as intact receptors, suggesting that the guanine nucleotide binding protein mediating GTP regulation of FSH binding in these membranes is probably Gs protein. Our results suggest that the bovine testis FSH receptor contains predominantly N-linked oligosaccharide chains consistent with recently predicted N-linked glycosylation sites of cloned FSH receptor of rat testis. The bovine testis FSH receptor does not require N-linked carbohydrate for high-affinity hormone binding.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Carbohydrate moiety of follitropin receptor is not required for high affinity hormone-binding or for functional coupling between receptor and guanine nucleotide-binding protein in bovine calf testis membranes. 142 41

ADP-ribosylation is a posttranslational modification of proteins by amino acid-specific ADP-ribosyltransferases. Both pertussis toxin and eukaryotic enzymes ADP-ribosylate cysteine residues in proteins and also, it has been suggested, free cysteine. Analysis of the reaction mechanisms of cysteine-specific ADP-ribosyltransferases revealed that free ADP-ribose combined nonenzymatically with cysteine. L- and D-cysteine, L-cysteine methyl ester, and cysteamine reacted with ADP-ribose, but alanine, serine, lysine, arginine, N-acetyl-L-cysteine, 2-mercaptoethanol, dithiothreitol, and glutathione did not. The 1H NMR spectrum of the product, along with the requirement for both free sulfhydryl and amino groups of cysteine, suggested that the reaction produced a thiazolidine linkage. ADP-ribosylthiazolidine was labile to hydroxylamine and mercuric ion, unlike the ADP-ribosylcysteine formed by pertussis toxin and NAD in guanine nucleotide-binding (G-) proteins, which is labile to mercuric ion but stable in hydroxylamine. In the absence of G-proteins but in the presence of NAD and cysteine, pertussis toxin generated a hydroxylamine-sensitive product, suggesting that a free ADP-ribose intermediate, expected to be formed by the NADase activity of the toxin, reacted with cysteine. Chemical analysis, or the use of alternative thiol acceptors lacking a free amine, is necessary to distinguish the enzymatic formation of ADP-ribosylcysteine from nonenzymatic formation of ADP-ribosylthiazolidine, thereby differentiating putative NAD:cysteine ADP-ribosyltransferases from NAD glycohydrolases.
...
PMID:Amino acid-specific ADP-ribosylation: structural characterization and chemical differentiation of ADP-ribose-cysteine adducts formed nonenzymatically and in a pertussis toxin-catalyzed reaction. 144 18

To determine whether direct stimulation of endothelial G-proteins causes relaxations of the underlying vascular smooth muscle, the effects of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and sodium fluoride were studied in porcine coronary arteries and endothelial cells. Isometric tension was measured in coronary rings contracted with prostaglandin F2 alpha. GTP gamma S (in the presence of saponin) and sodium fluoride (in the presence of AlCl3) relaxed rings with, but not those without endothelium. The responses were inhibited by nitro-L-arginine and pertussis toxin. In membrane fractions of coronary endothelial cells, GTP gamma S and sodium fluoride inhibited the ADP-ribosylation of G-proteins catalyzed with [32P]-NAD and pertussis toxin. These data suggest that direct stimulation of G-proteins in endothelial cells by GTP gamma S and sodium fluoride causes a pertussis toxin-sensitive relaxation which may be attributed to the release of nitric oxide.
...
PMID:Guanosine 5'-O-(3-thiotriphosphate) causes endothelium-dependent, pertussis toxin-sensitive relaxations in porcine coronary arteries. 144 86

A guanine nucleotide regulatory protein (G-protein) was purified to homogeneity from rat brain membrane though a series of chromatography runs, including DE-52 ion exchange, AcA-34 ultrogel, and octyl-Sepharose columns. The purified G-protein consisted of 3 subunits with molecular weights of 41000, 36000, and 8000, respectively. The alpha-subunit of the G-protein possessed high affinity GTP binding sites (k = 22.5 nmol/L) and GTPase activity (Km = 82.5 nmol/L, Vmax = 2.8 pmol/min/microgram protein), and it could be ADP-ribosylated by [adenylate-32P]-NAD in the presence of pertussis toxin. These results suggest that the purified protein was Gi-protein.
...
PMID:The purification of a guanine nucleotide regulatory protein from rat brain membrane and the measurement of its GTPase. 145 Mar 95

The ADP-ribosyl moiety of NAD was transferred to a 40-kDa protein when rat liver nuclei were incubated with pertussis toxin. The 40-kDa substrate in the nuclei displayed unique properties as follows, some of which were apparently distinct from those observed with the toxin-substrate GTP-binding protein (Gi) in the liver plasma membranes. 1) The nuclear 40-kDa protein was recognized with antibodies reacting with the alpha-subunits (alpha i-1 and alpha i-2) of Gi, but not with anti-Go-alpha-subunit antibody. 2) The nuclear protein had a higher mobility than alpha-subunit of the plasma membrane-bound Gi upon electrophoresis with a urea/sodium dodecyl sulfate-containing polyacrylamide gel. 3) The nuclear protein was not extracted from the nuclei with 1% Triton X-100, whereas Gi was easily solubilized from the plasma membranes. 4) There was a beta gamma-subunit-like activity in the nuclei, which was assayed by an ability to support pertussis toxin-catalyzed ADP-ribosylation of a purified alpha-subunit of Gi. Moreover, a 36-kDa protein in the nuclei was recognized with antibody raised against purified beta-subunits of Gi. 5) Pertussis toxin-induced ADP-ribosylation of the nuclear protein was selectively inhibited by the addition of a nonhydrolyzable GTP analogue, and its inhibitory action was competitively blocked by the simultaneous addition of GDP or its analogues, as had been observed with plasma membrane-bound Gi. It thus appeared that a novel form of alpha beta gamma-trimeric GTP-binding protein serving as the substrate of pertussis toxin was present in rat liver nuclei. In order to examine a possible role of the nuclear GTP-binding protein, rats were injected with carbon tetrachloride, a necrosis inducer of hepatocytes. There was a marked increase in the nuclear substrate activity from 3-6 days after the injection, without a significant change in the activity of Gi in the plasma membranes. The time course of the increase corresponded with a recovering stage from the hepatocyte necrosis. These results suggested that the nuclear GTP-binding protein found in the present study might be involved at some stages in the hepatocyte growth.
...
PMID:A GTP-binding protein in rat liver nuclei serving as the specific substrate of pertussis toxin-catalyzed ADP-ribosylation. 154 91

In an attempt to identify proteins involved in the secretory response, bovine chromaffin cells were modified with N-ethylmaleimide (NEM). NEM concentrations less than 30 microM enhanced norepinephrine secretion evoked by nicotine or by K+ depolarization and increased Ca(2+)-dependent secretion from digitonin-permeabilized cells. Higher concentrations of NEM inhibited secretion. The protein modified by NEM which was responsible for the enhancement of secretory activity appeared to rapidly diffuse out of the digitonin-permeabilized cells. When proteins which diffuse from control digitonin-permeabilized cells were incubated with pertussis toxin and [32P]NAD, several proteins were ADP-ribosylated. However, when proteins from cells preincubated with 30 microM NEM were incubated with pertussis toxin and [32P]NAD, these GTP-binding proteins (G-proteins) were not ADP-ribosylated, which suggests that they were modified in the cell by NEM. Stimulation of norepinephrine secretion by NEM was not additive with that caused by pertussis toxin. Modification of chromaffin cells with pertussis toxin or with 30 microM NEM caused a 40-50% decrease in the amount of cytoskeletal F-actin. This decrease in cytoskeletal F-actin may account for the increase in secretory activity.
...
PMID:Modification of chromaffin cells with pertussis toxin or N-ethylmaleimide lowers cytoskeletal F-actin and enhances Ca(2+)-dependent secretion. 156 91

A novel enzyme activity was found in bovine brain cytosol that transfers the ADP-ribosyl moiety of NAD to proteins with Mr values of 22,000 and 25,000. The substrates were the same GTP-binding proteins serving as the substrate of an ADP-ribosyltransferase C3 which was produced by a type C strain of Clostridium botulinum. The brain enzyme was partially purified from the cytosol and had a molecular mass of approximately 20,000 on a gel filtration column. The brain endogenous enzyme displayed unique properties similar to those observed with botulinum C3 enzyme. The enzyme activity was markedly stimulated by a protein factor that had been initially found in the cytosol as an activator for botulinum C3-catalyzed ADP-ribosylation (Ohtsuka, T., Nagata, K., Iiri, T., Nozawa, Y., Ueno, K., Ui, M., and Katada, T. (1989) J. Biol. Chem. 264, 15000-15005). The activity of the brain enzyme was also affected by certain types of detergents or phospholipids. The substrate of the brain enzyme was specific for GTP-binding proteins serving as the substrate of botulinum C3 enzyme; the alpha-subunits of trimeric GTP-binding proteins which served as the substrate of cholera or pertussis toxin were not ADP-ribosylated by the endogenous enzyme. Thus, this is the first report showing an endogenous enzyme in mammalian cells that catalyzes ADP-ribosylation of small molecular weight GTP-binding proteins.
...
PMID:Identification of a botulinum C3-like enzyme in bovine brain that catalyzes ADP-ribosylation of GTP-binding proteins. 164 35

Secretion of pulmonary surfactant by type II pulmonary epithelial cells (T2P) is regulated by receptor-mediated mechanisms. In other systems, coupling of receptor-linked signals to intracellular events involves guanine nucleotide-binding proteins (G proteins), but the specific role of G proteins in T2P signaling pathways is poorly defined. The present studies begin to address the role of G proteins in transmembrane signaling in these pneumocytes. Membrane preparations from purified T2Ps demonstrated ADP ribosylation of specific substrates by pertussis, cholera, and botulinum toxins (PT, CT, and BT, respectively). Toxin-dependent T2P substrate labeling from 32P-labeled NAD was dependent on time and membrane protein concentration. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography showed ADP ribosylation of membrane substrates of the following molecular masses: PT, 40/41 kDa; CT, 47/51 kDa; BT, 22 kDa. BT-dependent ADP ribosylation of a 22-kDa cytosolic substrate was also observed. Pretreatment of cultured T2P with the individual toxins led to ADP ribosylation of their respective specific substrates in a time-dependent fashion. In cells pretreated with PT or CT, substrates for the complimentary toxins remained available for subsequent ADP ribosylation in vitro. This result supports the specificity of the toxin effects. Basal secretion of the major phospholipid of pulmonary surfactant, disaturated phosphatidylcholine (DSPC) was unaffected in T2P treated with PT, but was stimulated in cells exposed to CT or BT. Neither CT nor BT altered release of lactate dehydrogenase. In cells treated with AMP or with isoproterenol DSPC secretion was stimulated six- to eightfold; preexposure of the cells to CT reduced the response to either agonist by 70%.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:ADP ribosylation of type II pulmonary epithelial cell G proteins. 164 81

An egg-specific NADase has been purified to homogeneity from the ovotestis of the opisthobranch mollusk Aplysia californica. Unlike other NADases, the Aplysia enzyme generates primarily cyclic-ADP-ribose (cADPR) rather than ADP-ribose from NAD. cADPR has been shown to stimulate the release of Ca2+ from microsomes prepared from sea urchin egg and, when injected into intact eggs, to activate the cortical reaction, multiple nuclear cycles, and DNA synthesis. The Aplysia enzyme was initially identified as an inhibitor of cholera and pertussis toxin-catalyzed ADP-ribosylation. By the use of an NADase assay, it was purified from the aqueous-soluble fraction of ovotestis by sequential column chromatography. The enzyme has an apparent molecular mass of 29 kDa, a Km for NAD of 0.7 mM, and a turnover rate of approximately 27,000 mol NAD.min-1.mol enzyme-1 at 30 degrees C. Monoclonal antibodies were generated to the NADase. Immunoblots of two-dimensional gels revealed multiple isoforms of the enzyme, with pls ranging from 8.1 to 9.8. The multiple isoforms were resolved with a cation exchange high-pressure liquid chromatography column and shown to generate cADPR. Immunohistochemical analysis of cryostat sections of Aplysia ovotestis shows that the enzyme is specific to the eggs and restricted to large 5- to 10-microns granules or vesicles. To date the cADPR-generating enzyme activity has been identified in various organisms, including mammals. The Aplysia enzyme is the first example in which the enzyme that generates cADPR has been purified. All of the available evidence indicates that this NADase is a second-messenger enzyme, implying that other NADases may serve a similar function.
...
PMID:Purification and characterization of a molluscan egg-specific NADase, a second-messenger enzyme. 165 Feb 54

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