Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.4.2.30 (PARP)
13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of ADP ribosylation of proteins in the physiological regulation of sporulation in Streptomyces griseus was studied. We report here that both the activity of NAD+: arginine ADP-ribosyltransferase (ADPRT) and the pattern of ADP-ribosylated proteins showed characteristic changes during the life cycle in S. griseus 2682. Analysis off ADP-ribosylated proteins revealed that in a nonsporulating mutant of the parental wild-type (wt) strain (Bld7 mutant), both the activity of ADPRT and the pattern of ADP-ribosylated proteins were different from those of the parental strain. Addition of 3-aminobenzamide (3AB), the most potent inhibitor of ADPRT, inhibited sporulation of S. griseus 2682 and the A-factor (AF)-induced sporulation of S. griseus Bld7, but in both cases the inhibitory effect of 3AB was strictly age-dependent. Using [alpha-32P]GTP, we have demonstrated the presence of GTP-binding proteins in purified cell membranes of S. griseus 2682 and S. griseus Bld7. The same GTP-binding proteins were observed in Bld7 and the wt. AF stimulated the basal GTPase activity of cell membranes of S. griseus 2682 in a concentration-dependent manner, suggesting that GTP-binding proteins might be involved in the AF-induced sporulation process.
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PMID:The possible role of ADP ribosylation in physiological regulation of sporulation in Streptomyces griseus. 161 34

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.
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PMID:Identification of a botulinum C3-like enzyme in bovine brain that catalyzes ADP-ribosylation of GTP-binding proteins. 164 35

1. An ADP-ribosyltransferase activity which appears to be capable of activating adenylyl cyclase was identified in a plasma membrane fraction from rabbit corpora lutea and partially characterized by comparing the properties of the luteal transferase with those of cholera toxin. 2. Incubation of luteal membranes in the presence of GTP and varying concentrations of NAD resulted in concentration-dependent increases in adenylyl cyclase activity. 3. Stimulation of adenylyl cyclase by NAD and cholera toxin plus NAD was observed in the presence of GTP but not in the presence of guanosine-5'-O-(2-thiodiphosphate) or guanyl-5'-yl imidodiphosphate. 4. NAD or cholera toxin plus NAD reduced the Kact values for luteinizing hormone to activate adenylyl cyclase 3- to 3.5-fold. 5. NAD or cholera toxin plus NAD increased the extent to which cholate extracts from luteal membranes were able to reconstitute adenylyl cyclase activity in S49 cyc- mouse lymphoma membranes. 6. It was necessary to add ADP-ribose and arginine to the incubation mixture in order to demonstrate cholera toxin-specific ADP-ribosylation of a protein corresponding to the alpha subunit of the stimulatory guanine nucleotide-binding regulatory component (alpha Gs). 7. Treatment of luteal membranes with NAD prior to incubation in the presence of [32P]NAD plus cholera toxin resulted in reduced labeling of alpha Gs. 8. Endogenous ADP-ribosylation of alpha Gs was enhanced by Mg but was not altered by guanine nucleotide, NaF or luteinizing hormone and was inhibited by cAMP. 9. Incubation of luteal membranes in the presence of [32P]ADP-ribose in the absence and presence of cholera toxin did not result in the labeling of any membrane proteins.
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PMID:Evidence for a rabbit luteal ADP-ribosyltransferase activity which appears to be capable of activating adenylyl cyclase. 164 18

Pertussis toxin is an ADP-ribosyltransferase which alters the function of some of the GTP-binding proteins and inhibits some actions of insulin. In vivo, pertussis toxin (2 micrograms/ml/2h) inhibited insulin-stimulated tyrosyl autophosphorylation of the insulin receptor by 50% in FaO cells, and nearly completely inhibited phosphorylation of the cellular insulin receptor substrate pp185. Similarly, insulin-stimulated autophosphorylation and kinase activity of the insulin receptor purified on wheat germ agglutinin-agarose from pertussis toxin-treated FaO cells was diminished 50%; however, treatment of cells with the catalytically inactive B-oligomer of the toxin had no effect on receptor tyrosine kinase activity in vitro. Pertussis toxin did not alter insulin binding or the cellular levels of ATP, cAMP, and cGMP. Furthermore, immunoprecipitation of the insulin receptor from intact cells with anti-insulin receptor antibodies showed that pertussis toxin did not increase the phosphorylation of serine or threonine residues in the insulin receptor. These results suggest that pertussis toxin can modulate signal transduction of insulin at the level of the insulin receptor kinase.
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PMID:Pertussis toxin inhibits autophosphorylation and activation of the insulin receptor kinase. 172 5

In rat liver cytosol, rapid ADP-ribosylation of a 52 kDa protein by endogenous ADP-ribosyltransferase(s) was observed. This ADP-ribosylation was stimulated dose-dependently by 14,15-epoxyeicosatrienoic acid (14,15-EET), one of the metabolites of arachidonic acid by NADPH-dependent cytochrome P-450 mono-oxygenase. This stimulatory effect required the presence of GTP or its non-hydrolysable analogues, guanosine 5'-[beta gamma-imido]triphosphate or guanosine 5'-[gamma-thio]triphosphate. Of four regioisomeric EETs, 14,15-EET was the most potent. No stimulatory effect was observed with addition of 14,15-dihydroxyeicosatrienoic acid, a stable metabolite of 14,15-EET. The 52 kDa protein was not ADP-ribosylated by cholera toxin A subunit and pertussis toxin, and was not recognized by anti-Gs alpha and anti-Gi alpha antibodies. However, the 52 kDa protein could be photoaffinity-labelled with 8-azidoguanosine 5'-[alpha-32P]triphosphate. These results suggest that the 52 kDa protein is neither Gs nor Gi, though it may have a GTP-binding site. These results contribute to the understanding of the role of mono-oxygenase metabolites of arachidonic acid in intracellular signal transduction.
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PMID:Epoxyeicosatrienoic acid stimulates ADP-ribosylation of a 52 kDa protein in rat liver cytosol. 173 54

ADP-ribosylation factors (ARFs) are a family of approximately 20-kDa guanine nucleotide-binding proteins initially identified by their ability to enhance cholera toxin ADP-ribosyltransferase activity in the presence of GTP. ARFs have been purified from both membrane and cytosolic fractions. ARF purified from bovine brain cytosol requires phospholipid plus detergent for high affinity guanine nucleotide binding and for optimal enhancement of cholera toxin ADP-ribosyltransferase activity. The phospholipid requirements, combined with a putative role for ARF in vesicular transport, suggested that the soluble protein might interact reversibly with membranes. A polyclonal antibody against purified bovine ARF (sARF II) was used to detect ARF by immunoblot in membrane and soluble fractions from rat pheochromocytoma (PC-12) cell homogenates. ARF was predominantly cytosolic but increased in membranes during incubation of homogenates with nonhydrolyzable GTP analogues guanosine 5'-O-(3-thiotriphosphate), guanylyl-(beta gamma-imido)-diphosphate, and guanylyl-(beta gamma-methylene)-diphosphate, and to a lesser extent, adenosine 5'-O-(3-thiotriphosphate). GTP, GDP, GMP, and ATP were inactive. Cytosolic ARF similarly associated with added phosphatidylserine, phosphatidylinositol, or cardiolipin in GTP gamma S-dependent fashion. ARF binding to phosphatidylserine was reversible and coincident with stimulation of cholera toxin-catalyzed ADP-ribosylation. These observations may reflect a mechanism by which ARF could cycle between soluble and membrane compartments in vivo.
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PMID:GTP but not GDP analogues promote association of ADP-ribosylation factors, 20-kDa protein activators of cholera toxin, with phospholipids and PC-12 cell membranes. 173 79

ADP-ribosylation factors (ARFs) are approximately 20-kDa guanine nucleotide-binding proteins that stimulate the ADP-ribosyltransferase activity of cholera toxin in vitro. Five different human ARFs have been identified by cDNA cloning. Northern analysis using ARF 3-specific oligonucleotides identified two mRNAs of 3.7 and 1.2 kilobases (kb). We report here the complete nucleotide sequence of the 3.7-kb ARF 3 mRNA derived from three overlapping cDNAs isolated from human hippocampus and fetal brain cDNA libraries, as well as the structure of human ARF 3 gene. Sequences of two overlapping genomic clones indicated that the ARF 3 gene spans approximately 18.3 kb and contains five exons and four introns. The conserved amino acid sequences involved in guanine nucleotide binding by ARF 3 are distributed among separate exons, as found in other GTP-binding protein genes. Translation initiates in exon 2 which includes the sequence GXXXXGK that probably participates in phosphate binding and GTP hydrolysis. The sequence DVGG in exon 3 coordinates binding of Mg2+ and the beta-phosphate of GDP. In the ARF 3 gene in contrast to those of other GTP-binding proteins, the sequence NKXD (which is thought to contribute to the specificity of interaction with the guanine ring) is divided between exons 4 and 5. The latter encodes the COOH-terminal 53 amino acids of ARF 3 and contains greater than 2500 base pairs of untranslated DNA. The sequence AATTAA is 19 bases 5' to the polyadenylation addition site of the 3.7-kb mRNA. Multiple transcription start sites were identified by primer extension and S1 and mung bean nuclease analyses. The 5'-flanking region of exon 1 contains neither a TATA nor a CAAT box, but is high in GC content (greater than 70%) and includes three potential Sp1-binding sites (GC box), consistent with the promoters described for several housekeeping genes. The 1.2-kb ARF 3 mRNA is shown to arise by use of an alternative polyadenylation signal (AACAAA) at nucleotide 1091 within the ARF 3 cDNA.
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PMID:Isolation and characterization of the human gene for ADP-ribosylation factor 3, a 20-kDa guanine nucleotide-binding protein activator of cholera toxin. 174 2

In bovine aortic smooth muscle, GTP-binding activity was equally distributed in the membrane and cytosol fractions. The most abundant GTP-binding proteins (G proteins) in each fraction were purified to near homogeneity and characterized. The most abundant G protein in the membrane fraction had a Mr value of about 22,000 (m22K G) as estimated on sodium dodecyl sulfate-polyacryl-amide gel electrophoresis (SDS-PAGE). m22K G and the human platelet smg p21, a ras p21 like G protein having the same effector domain as ras p21s, were eluted at the same retention time on C4 reversed-phase high performance liquid chromatography (HPLC). Moreover, m22K G was specifically recognized by an anti-smg p21 polyclonal antibody. m22K G was phosphorylated by cyclic AMP-dependent protein kinase with a stoichiometry of one phosphate/molecule of protein. The most abundant G protein in the cytosol fraction had a Mr value of about 21,000 (c21K G) as estimated on SDS-PAGE. c21K G was ADP-ribosylated by botulinum ADP-ribosyltransferase and about 0.4 mol of ADP-ribose was maximally incorporated into 1 mol of c21K G. c21K G and the bovine brain rhoA p21, another ras p21 like G protein, were eluted at the same retention time on C4 reversed-phase HPLC and migrated at the same position on two-dimensional gel electrophoresis. These results indicate that the major G proteins in the membrane and cytosol fractions of bovine aortic smooth muscle are smg p21 and rhoA p21, respectively. Possible roles of these G proteins in vascular smooth muscle are discussed.
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PMID:Small GTP-binding proteins in bovine aortic smooth muscle. 174 79

Pretreatment of rho protein purified from pig brain cytosol with EDTA (3 mM) for 10 min at 30 degrees C inhibited its ADP-ribosylation by Clostridium botulinum C3 ADP-ribosyltransferase by more than 90%. The EDTA effect was not caused by alteration of C3. GDP or GDP beta S present during the pretreatment period completely prevented the decrease in ADP-ribosylation with half-maximal and maximal effects at 3 and 300 microM, respectively. GTP or GTP gamma S were less efficacious in preventing the decrease in ADP-ribosylation, but were more potent (half-maximal and maximal effects at 0.1 and 3 microM, respectively). [32P]ADP-ribose incorporated in pig brain rho by C3 was de-ADP-ribosylated by the enzyme in the presence of nicotinamide and at low pH. Concomitantly, [32P]NAD was formed. The pH optima for ADP-ribosylation and de-ADP-ribosylation were pH 7.5 and 5.5, respectively. De-ADP-ribosylation was most efficient with nicotinamide, less effective with 3-acetylpyridine and not observed with 3-aminopyridine, 4-aminopyridine, 4-acetylpyridine and isonicotinic acid. As observed for the ADP-ribosylation, the de-ADP-ribosylation by C3 was maximal with the GDP-bound form of rho and blocked after EDTA treatment.
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PMID:ADP-ribosylation and de-ADP-ribosylation of the rho protein by Clostridium botulinum exoenzyme C3. Regulation by EDTA, guanine nucleotides and pH. 182 95

Degranulation of neutrophils involves the differential regulation of the exocytosis of at least two populations of granules. Low molecular weight GTP-binding proteins (LMW-GBPs) have been implicated in the regulation of vesicular traffic in the secretory pathways of several types of cells. In the present study we identify distinct subsets of LMW-GBPs associated with the membranes of neutrophil-specific and azurophilic granules. Ninety-four percent of total [35S]guanosine 5'-(3-O-thio)triphosphate (GTP gamma S) binding activity was equally distributed between the plasma membrane and cytosol with the remaining 6% localized in the granules. In contrast, the cytosol contained only 10% of the total GTPase activity while the specific granules accounted for 13%. [alpha-32P]GTP binding to proteins transferred to nitrocellulose revealed LMW-GBPs in all fractions except the azurophilic granules. The specific granules contained three out of four bands which were found in the plasma membrane; these ranged from 20 to 23 kDa and all were resistant to alkaline extraction. Photoaffinity labeling with [alpha-32P]8-azido-GTP in the presence of micromolar Al3+ identified proteins of 25 and 26 kDa unique to azurophilic granules; these could not be labeled with [alpha-32P]8-azido-ATP and could be extracted by acidic but not alkaline pH. Botulinum C3-mediated [32P]ADP-ribosylation identified proteins of 16, 20, and 24 kDa both in plasma membranes and those of specific granules. An anti-ras monoclonal antibody, 142-24E5, recognized a 20-kDa protein localized to the plasma and specific granule membranes which could not be extracted by alkaline pH, was not a substrate for botulinum C3 ADP-ribosyltransferase, and was translocated from specific granules to plasma membrane after exposure of neutrophils to phorbol myristate acetate. We conclude that neutrophil-specific and azurophilic granules contain distinct subsets of LMW-GBPs which are uniquely situated to regulate the differential exocytosis of these two compartments.
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PMID:Low molecular weight GTP-binding proteins in human neutrophil granule membranes. 189 32


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