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Banno Y, Suzuki T, Nozawa Y. Isolation of a Polyphosphoinositide-phospholipase C (Type β) from Cytosolic and Membrane Fractions of Human Platelets. Platelets 2009; 3:69-77. [DOI: 10.3109/09537109209003390] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
The onset of development in most species studied is triggered by one of the largest and longest calcium transients known to us. It is the most studied and best understood aspect of the calcium signals that accompany and control development. Its properties and mechanisms demonstrate what embryos are capable of and thus how the less-understood calcium signals later in development may be generated. The downstream targets of the fertilization calcium signal have also been identified, providing some pointers to the probable targets of calcium signals further on in the process of development. In one species or another, the fertilization calcium signal involves all the known calcium-releasing second messengers and many of the known calcium-signalling mechanisms. These calcium signals also usually take the form of a propagating calcium wave or waves. Fertilization causes the cell cycle to resume, and therefore fertilization signals are cell-cycle signals. In some early embryonic cell cycles, calcium signals also control the progress through each cell cycle, controlling mitosis. Studies of these early embryonic calcium-signalling mechanisms provide a background to the calcium-signalling events discussed in the articles in this issue.
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Affiliation(s)
- Michael Whitaker
- Institute of Cell and Molecular Biology, Newcastle University Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Moolenaar WH, van Corven EJ. Growth factor-like action of lysophosphatidic acid: mitogenic signalling mediated by G proteins. CIBA FOUNDATION SYMPOSIUM 2007; 150:99-106; discussion 106-11. [PMID: 2115427 DOI: 10.1002/9780470513927.ch7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Several classes of growth factors can be distinguished that act through different signal transduction pathways. One class is constituted by the peptide growth factors that bind to receptors with ligand-dependent protein tyrosine kinase activity. Another class of mitogens activates a phosphoinositide-specific phospholipase C via a receptor-linked G protein. An intriguing member of this class is lysophosphatidic acid (LPA). LPA mitogenicity is not dependent on other mitogens and is blocked by pertussis toxin. LPA evokes at least three separate signalling cascades: (i) activation of a pertussis toxin-insensitive G protein mediating phosphoinositide hydrolysis; (ii) release of arachidonic acid in a GTP-dependent manner, but independent of prior phosphoinositide hydrolysis; and (iii) activation of a pertussis toxin-sensitive Gi protein mediating inhibition of adenylate cyclase. The peptide bradykinin mimics LPA in inducing responses (i) and (ii), but fails to activate Gi and to stimulate DNA synthesis. Our results suggest that the mitogenic action of LPA occurs through Gi or a related pertussis toxin substrate and that, unexpectedly, the phosphoinositide hydrolysis pathway is neither required nor sufficient, by itself, for mitogenesis.
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Affiliation(s)
- W H Moolenaar
- Division of Cellular Biochemistry, Netherlands Cancer Institute, Amsterdam
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Pedrosa MM, Mateos JL, Caffaro SV, Legaz ME, Vicente C. Separation of Cyclic GMP AND Cyclic AMP from Other Nucleotides by Reverse Phase Hplc. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10826079208018324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kolb HA, Somogyi R. Biochemical and biophysical analysis of cell-to-cell channels and regulation of gap junctional permeability. Rev Physiol Biochem Pharmacol 2005; 118:1-47. [PMID: 1721723 DOI: 10.1007/bfb0031480] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- H A Kolb
- University of Konstanz, Faculty of Biology, FRG
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Giusto NM, Pasquaré SJ, Salvador GA, Castagnet PI, Roque ME, Ilincheta de Boschero MG. Lipid metabolism in vertebrate retinal rod outer segments. Prog Lipid Res 2000; 39:315-91. [PMID: 10856601 DOI: 10.1016/s0163-7827(00)00009-6] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- N M Giusto
- Instituto de Investigaciones Bioquímicas, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, CC 857, B 8000 FWB, Bahia Blanca, Argentina.
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Affiliation(s)
- Z Y Friedman
- Department of Biological Chemistry, Hebrew University of Jerusalem, Israel
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Lou LG, Ma L, Pei G. Nociceptin/orphanin FQ activates protein kinase C, and this effect is mediated through phospholipase C/Ca2+ pathway. Biochem Biophys Res Commun 1997; 240:304-8. [PMID: 9388473 DOI: 10.1006/bbrc.1997.7654] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effect of nociceptin/orphanin FQ (N/OFQ) on protein kinase C (PKC) was investigated in Chinese hamster ovary cells stably expressing opioid receptor-like (ORL1) receptor (CHO-ORL1 cells). N/OFQ significantly activated PKC in CHO-ORL1 cells with EC50 of 0.2 nM. This response was blocked by PKC inhibitors chelerythrine and Gö 6976, and by pretreatment of cells with pertussis toxin (PTX). The inhibition of PKC activation by N/OFQ was also achieved by use of Ca(2+)-chelators and phospholipase C (PLC) inhibitor U-73122. These results indicate that N/OFQ can effectively activate PKC via ORL1 receptor, and suggest the activation involve the PLC/Ca2+ system.
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Affiliation(s)
- L G Lou
- Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China
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Le Mellay V, Grosse B, Lieberherr M. Phospholipase C beta and membrane action of calcitriol and estradiol. J Biol Chem 1997; 272:11902-7. [PMID: 9115251 DOI: 10.1074/jbc.272.18.11902] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have shown that estrogens and calcitriol, the hormonally active form of vitamin D, increase the concentration of intracellular calcium ([Ca2+]i) within 5 s by mobilizing calcium from the endoplasmic reticulum and the formation of inositol 1,4, 5-trisphosphate and diacylglycerol. Because the activation of effectors as phospholipase C (PLC) coupled to G-proteins is the early event in the signal transduction pathway leading to the inositol 1,4,5-trisphosphate formation and to [Ca2+]i increase, we described different PLC isoforms (beta1, beta2, gamma1, and gamma2, but not beta4) in female rat osteoblasts using Western immunoblotting. The data showed that phospholipase C beta was involved in the mobilization of Ca2+ from the endoplasmic reticulum of Fura-2-loaded confluent osteoblasts by calcitriol and 17beta estradiol, and PLC gamma was ineffective. The data also showed that only a PLC beta1 linked to a Pertussis toxin-insensitive G-protein and a PLC beta2 coupled to a Pertussis toxin-sensitive G-protein are involved in the effects of calcitriol and 17beta estradiol on the mobilization of Ca2+ from intracellular Ca2+ stores. In conclusion, these results may be an important step toward understanding membrane effects of these steroids and may be an additional argument in favor of membrane receptors to steroid hormones.
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Affiliation(s)
- V Le Mellay
- CNRS, URA 583, Université Paris V, 78 350 Jouy-en-Josas, France
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11
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Abstract
Our previous studies have shown that intraperitoneal administration of DOI [(+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane] simultaneously produces the head-twitch and ear-scratch responses (HTR and ESR, respectively) in mice via activation of 5-HT2A receptors. In the present study, we have investigated the ontogeny of these DOI-induced behaviors in both male and female mice across a wide age range (i.e., postnatal days 7, 14, 18, 22, 28, 35, 42, 63, 120, and 180). We also measured the effects of DOI on the locomotor activity of these mice. In addition to the vehicle, 2 doses of DOI (1 and 2.5 mg/kg) were used in age-matched different male and female groups. The age of onset for significant production of HTR and ESR by both doses of DOI were between postpartum days 14-18 and 18-22, respectively. Maximal HTR frequency to both doses of DOI (66 and 94 HTRs) occurred on postpartum day 28. Thereafter, the HTR frequency tended to decrease with increasing age, but the attenuation did not attain significance. On the other hand, maximal ESR score (37 and 60 ESRs) generally developed between postpartum days 22-35 for the cited doses of DOI. After 35 days of age, the ESR frequency dramatically decreased and, by postnatal day 180, no significant response was obtained to either dose of DOI. Age-matched vehicle-treated male and female control groups exhibited few (1-8) HTRs and ESRs across the age range tested. DOI dose-dependently enhanced locomotor activity in both male and female mice relative to their age- and sex-matched vehicle-treated controls for the first 28 days of life. Thereafter, no significant effect was observed. None of the cited behaviors exhibited gender differences across the age range tested. The present results suggest that DOI-induced changes in HTR, ESR, and locomotor activity develop and mature differentially, but in a similar manner, in male and female mice. Furthermore, unlike DOI-induced HTR, the ability of DOI to produce ear-scratches and to enhance locomotor activity in mice disappears with old age.
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Affiliation(s)
- N A Darmani
- Department of Pharmacology, Kirksville College of Osteopathic Medicine, MO 63501, USA
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Tamir H, Liu KP, Adlersberg M, Hsiung SC, Gershon MD. Acidification of serotonin-containing secretory vesicles induced by a plasma membrane calcium receptor. J Biol Chem 1996; 271:6441-50. [PMID: 8626445 DOI: 10.1074/jbc.271.11.6441] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Parafollicular (PF) cells secrete 5-hydroxytryptamine in response to increased extracellular Ca2+ ([Ca2+]e). This stimulus causes Cl- channels in PF secretory vesicles to open, leading to vesicle acidification. PF cells express a plasmalemmal heptahelical receptor (CaR) that binds Ca2+, Gd3+, and Ba2+. We now report that the CaR mediates vesicle acidification. Ca2+, Gd3+, and Ba2+ induced vesicle acidification, which was independent of channel-mediated Ca2+ entry. Agonist-induced vesicle acidification was blocked by pertussis toxin, inhibitors of phosphatidylinositol-phospholipase C, calmodulin, NO synthase, guanylyl cyclase, or protein kinase G. PF cells contained NO synthase immunoreactivity, and vesicles were acidified by NO donors and dibutyryl cGMP. [Ca2+]e, and Gd3+ mobilized thapsigargin-sensitive internal Ca2+ stores. [35S]G alpha i and [35S]G alpha q were immunoprecipitated from PF membranes incubated with agonists in the presence of [35S]adenosine 5'-O-(thiotriphosphate). Labeling of G alpha i but not G alpha q was antagonized by pertussis toxin. Vesicles acidified in response to activation of protein kinase C; however, protein kinase C inhibition blocked calcium channel- but not CaR-dependent acidification. We propose the following signal transduction pathway: CaR -> Gi -> phosphatidylinositol-phospholipase C -> inositol 1,4,5-trisphosphate -> [Ca2+]i -> Ca2+/calmodulin -> NO synthase -> NO -> guanylyl cyclase -> cGMP -> protein kinase G -> opens vesicular Cl- channel.
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Affiliation(s)
- H Tamir
- Division of Neuroscience, New York State Psychiatric Institute, New York 10032, USA
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Samii SI, Webb RA. The stimulatory effect of L-glutamate and related agents on inositol 1,4,5-trisphosphate production in the cestode Hymenolepis diminuta. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1996; 113:409-20. [PMID: 8697199 DOI: 10.1016/0742-8413(96)00007-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of L-glutamate, acetylcholine, and serotonin (5HT) were examined on generation of inositol 1,4,5-triphosphate [Ins(1,4,5)P3], in membrane preparations of the cestode Hymenolepis diminuta. Only L-glutamate and acetylcholine stimulated a significant elevation in Ins(1,4,5)P3. The response to L-glutamate was stereospecific; D-glutamate or L-aspartate were not as potent. A role for G-protein(s) was supported by the observations that sodium fluoride stimulated Ins(1,4,5)P3 generation, and the L-glutamate response was potentiated by GTP and GTP-S and was suppressed by GDPS. However, studies with pertussis and cholera toxins indicated that the putative G-protein(s) was not pertussis or cholera toxin sensitive. The pharmacological profile of the L-glutamate response was examined partially. Trans-ACPD was a very effective agonist at 10(-5)M. While 10(-3)M L-glutamate, NMDA, and AMPA significantly elevated Ins(1,4,5)P3 levels, quisqualate and kainate did not. The elevation of Ins(1,4,5)P3 levels by L-glutamate and NMDA was antagonized by the specific glutamatergic antagonists AP-5, AP-7, CNQX, and CPP. While the response to ACPD was antagonized by AP5, CPP and CPG, CNQX was without effect. Collectively, the data support the hypothesis that in the cestode H. diminuta, L-glutamate activation of a metabotropic (ACPD) and/or ionotropic-like AMPA/NMDA receptor subtypes proceeds via a G protein(s) to enhance phospholipase C activity, ultimately resulting in the elevation of Ins(1,4,5)P3 levels in the tissues.
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Affiliation(s)
- S I Samii
- Department of Biology, York University, Ontario, Canada
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Chen LC, Wu CY, Chen CF, Chiang CF. Purification of chlorpromazine-sensitive GTPase from rat cerebral cortex. PREPARATIVE BIOCHEMISTRY 1995; 25:183-95. [PMID: 8570568 DOI: 10.1080/10826069508010120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The chlorpromazine-sensitive GTPase from the cell membrane of rat cerebral cortex was purified to homogenity by using DEAE Bio-Gel A agarose, hydroxyapatite and heparin agarose chromatography. The purified chlorpromazine-sensitive GTPase was purified 370-fold to obtain a final specific activity of 40 mumol GTP hydrolyzed2min/mg protein. The purified enzyme was inhibited by chlorpromazine but not by compound 48/80. Magnesium was required for its activity instead of calcium. The purified enzyme had an apparent pH optimum of 8.0, and molecular weight was estimated to be 58,000.
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Affiliation(s)
- L C Chen
- Department of Pharmacology, National Yang-Ming University, Taipei, Taiwan, Republic of China
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Muñoz-Acedo G, Izquierdo-Claros RM, Sánchez-Alonso JA, del Hoyo N, Pérez-Albarsanz MA, Arilla E. Effect of somatostatin on the mass accumulation of inositol-1,4,5-trisphosphate in rat hypothalamus, striatum, frontoparietal cortex and hippocampus. Neurosci Lett 1995; 197:41-4. [PMID: 8545051 DOI: 10.1016/0304-3940(95)11896-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Somatostatin-14 (SS) significantly increased inositol-1,4,5-trisphosphate (IP3) accumulation in rat hypothalamic, striatal, frontoparietal cortical and hippocampal slices. However, this stimulation of IP3 accumulation by SS was highest in the frontoparietal cortex and hippocampus. The effect was already significant with 0.01 microM in the frontoparietal cortex (P < 0.05) and hippocampus (P < 0.05) and the maximal accumulation was evident with 0.1 microM SS, in all areas studied. A concentration of 1 microM SS, lacked this effect in hypothalamus and striatum. SS rapidly increased IP3 accumulation in all brain areas studied. This effect was maximal at 15 s of incubation and decreased subsequently. At 60 s incubation, levels were still elevated in frontoparietal cortex and hippocampus but had returned to basal values in hypothalamus and striatum. Somatostatin-28 (SS-28) and the SS analogues, D-Trp8-D-Cys14 and SMS 201-995, also significantly stimulated IP3 accumulation although the effect of SMS 201-995 was greater than that of SS in the striatum in comparison with controls (P < 0.001 and P < 0.01, respectively). These results suggest that SS action at the hypothalamus, striatum, frontoparietal cortex and hippocampus is mediated at least in part by the accumulation of IP3, which may initiate intracellular processes responsible for some biological SS effects.
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Affiliation(s)
- G Muñoz-Acedo
- Departamento de Bioquímica y Biología, Molecular, Facultad de Medicina, Universidad de Alcalá, Madrid, Spain
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Iqbal Z. Excitatory amino acid receptor-mediated neuronal signal transduction: modulation by polyamines and calcium. Mol Cell Biochem 1995; 149-150:233-40. [PMID: 8569734 DOI: 10.1007/bf01076582] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The excitatory amino acids (EAA), L-glutamate and L-aspartate were initially advanced as excitatory neurotransmitters some 30 years ago but in the past few years investigations on EAA have proceeded rapidly from the identification of the putative neurotransmitters and characterization of their receptors to the clarification of their role in development, learning, memory, and neuropathology. The NMDA(N-methyl-D-aspartate) class of glutamate receptor has been the subject of much recent interdisciplinary study, as NMDA receptors render over stimulated neurons susceptible to injury and death. This review is focused on the involvement of polyamines in EAA receptor-mediated neuronal signal transduction mechanisms.
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Affiliation(s)
- Z Iqbal
- Department of Neurology, School of Medicine, Northwestern University, Chicago, Illinois, USA
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Pelet C, Mironneau C, Rakotoarisoa L, Neuilly G. Angiotensin II receptor subtypes and contractile responses in portal vein smooth muscle. Eur J Pharmacol 1995; 279:15-24. [PMID: 7556378 DOI: 10.1016/0014-2999(95)00125-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The selective biphenylimidazole and tetrahydroimidazopyridine antagonists exemplified by losartan (DuP 753) and PD 123319 have been shown to bind selectively to angiotensin AT1 and AT2 receptor subtypes, respectively. To characterize which subtypes of angiotensin II receptors are expressed in mammalian portal vein smooth muscle, we performed, using both membrane and strip preparations, [3H]angiotensin II binding experiments and then contraction experiments to investigate the functional relevance of these binding sites. Specific binding of [3H]angiotensin II was of high affinity, saturable and reversible. Specific binding of [3H]angiotensin II was completely displaced by angiotensin II and the peptide antagonist [Sar1,Ile8]angiotensin II. The inhibition of [3H]angiotensin II binding by losartan (2-n-butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl)biphe nyl-4-yl)- methyl]imidazole, potassium salt) and DuP 532 (2-n-propyl-4-pentafluoroethyl-1-[(2'-(1H-tetrazol-5-yl)biph enyl-4-yl)- methyl]imidazole-5-carboxylic acid) was biphasic and LIGAND curve-fitting analysis revealed two populations of specific binding sites. One subpopulation represented 75% of the total binding and showed high affinity for angiotensin II, losartan and DuP 532, but low affinity for the peptide angiotensin AT2 receptor antagonist CGP 42112A (N-alpha-nicotinoyl-Tyr-Lys-[N-alpha-CBZ-Arg]-His-Pro-Ile-OH) and thus appeared identical to the cloned angiotensin AT1 receptor subtype. The remaining 25% of the sites showed nearly 1000-fold lower affinity for losartan, 6500-fold lower affinity for DuP 532 and high affinity for PD 123319 (S-1-[[4-(dimethylamino)-3-methylphenyl]methyl]-5-diphenylacetyl- 4,5,6,7-tetrahydro-1H-imidazo-[4,5-c] pyridine-6-carboxylic acid, difluoroacetate monohydrate) and CGP 42112A, with values of Ki in the same range (nM) as those found for losartan and DuP 532 at angiotensin AT1 binding sites. These sites appear to be angiotensin AT2 receptors. Only the angiotensin AT1 receptor subtype interacted with G-proteins, as indicated by the 80% inhibition of [3H]angiotensin II binding in the presence of guanosine 5'-O-(3-thiophosphate) or fluoroaluminates. Although the angiotensin II-induced contraction was completely inhibited by losartan with a pA2 value of 8.8, PD 123319 reduced the angiotensin II-induced contraction by 20-25%, indicating that both angiotensin AT1 and AT2 receptor subtypes are functional in portal vein smooth muscle.
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Affiliation(s)
- C Pelet
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, URA CNRS 1489, Université de Bordeaux II, France
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Prestwich SA, Miyazaki H, Bolton TB. Effects of GTP gamma S on muscarinic receptor-stimulated inositol phospholipid hydrolysis in permeabilized smooth muscle from the small intestine. Br J Pharmacol 1995; 115:147-57. [PMID: 7647969 PMCID: PMC1908765 DOI: 10.1111/j.1476-5381.1995.tb16332.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. Smooth muscle fragments from the longitudinal layer of the small intestine of the guinea-pig were permeabilized with Staphylococcus aureus alpha toxin (alpha-toxin) and used to investigate the role of G-protein activation in the regulation of muscarinic acetylcholine receptor (AChR)-stimulated inositol phospholipid hydrolysis. 2. The efficiency of alpha-toxin permeabilization was estimated by the release of [3H]-2-deoxyglucose ([3H]-2DG) after prior loading or lactate dehydrogenase (LDH) enzyme release from the smooth muscle fragments. 3. In alpha-toxin-permeabilized smooth muscle, but not in non-permeabilized muscle, GTP gamma S induced time- and concentration-dependent increases in labelled inositol phosphates. Carbachol (CCh) increased labelled inositol phosphates in both permeabilized and non-permeabilized muscle, although the increases were greater in non-permeabilized smooth muscle. The response to 100 microM CCh was severely reduced by 0.5 microM atropine. 4. In permeabilized muscle the effects of GTP gamma S or CCh on inositol phosphate levels were reduced by treatment with pertussis toxin (PTX) and completely inhibited by GDP beta S. 5. GTP gamma S caused a concentration-dependent inhibition of the CCh-induced increases in the levels of labelled inositol phosphates. Dibutyryl cyclic AMP or Sp-cAMPs (adenosine-3',5'-cyclic phosphorothiolate-Sp) reduced the effects of CCh on inositol phosphate levels. 6. The results suggest that muscarinic AChR activation induces inositol phospholipid hydrolysis via more than one G-protein in this smooth muscle and that several mechanisms may contribute to the modulation of both stimulatory and inhibitory responses observed.
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Affiliation(s)
- S A Prestwich
- Department of Pharmacology and Clinical Pharmacology, St George's Hospital Medical School, London
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Conn PM, Janovick JA, Stanislaus D, Kuphal D, Jennes L. Molecular and cellular bases of gonadotropin-releasing hormone action in the pituitary and central nervous system. VITAMINS AND HORMONES 1995; 50:151-214. [PMID: 7709600 DOI: 10.1016/s0083-6729(08)60656-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- P M Conn
- Oregon Regional Primate Research Center, Beaverton 97006
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20
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Ali N, Agrawal DK. Guanine nucleotide binding regulatory proteins: their characteristics and identification. J Pharmacol Toxicol Methods 1994; 32:187-96. [PMID: 7881132 DOI: 10.1016/1056-8719(94)90086-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Many biological signals are processed by the binding of chemicals to cell surface receptors. Signals are switched to intracellular language via guanine nucleotide binding regulatory proteins (G-proteins) which are present in all eukaryotic cells. Thus, G-proteins serve as interfaces between receptor-response coupling. Two forms of G-proteins have been reported: conventional G-proteins which are heterotrimeric and consist of alpha, beta, and gamma subunits, and monomeric small molecular weight G-proteins which are generally found as single polypeptides. Recently, high molecular weight G-proteins have also been described. The family of G-proteins contains multiple genes that encode the alpha, beta, or gamma subunits. G-proteins play a pivotal role in excitation-contraction coupling in smooth muscle function and control metabolic and secretory processes. In this review article, we have given a brief overview on the characteristics and methodology for the identification of G-proteins. The heterotrimeric G-proteins are generally identified by Western blotting and ADP-ribosylation with bacterial toxins. The monomeric and high molecular weight G-proteins have been identified by [35S]GTP delta S overlay technique and photoaffinity labeling, respectively. Recently, the use of molecular genetic probes has made it possible to investigate the expression of the message for various G-proteins.
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Affiliation(s)
- N Ali
- Department of Internal Medicine, Creighton University School of Medicine, Omaha, Nebraska 68178
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Sánchez-Margalet V, Goberna R. Pancreastatin activates pertussis toxin-sensitive guanylate cyclase and pertussis toxin-insensitive phospholipase C in rat liver membranes. J Cell Biochem 1994; 55:173-81. [PMID: 7916348 DOI: 10.1002/jcb.240550204] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have recently found the calcium dependent glycogenolytic effect of a pancreastatin on rat hepatocytes and the mobilization of intracellular calcium. To further investigate the mechanism of action of pancreastatin on liver we have studied its effect on guanylate cyclase, adenylate cyclase, and phospholipase C, and we have explored the possible involvement of GTP binding proteins by measuring GTPase activity as well as the effect of pertussis toxin treatment of plasma liver membranes on the pancreastatin stimulated GTPase activity and the production of cyclic GMP and myo-inositol 1,4,5-triphosphate. Pancreastatin stimulated GTPase activity of rat liver membranes about 25% over basal. The concentration dependency curve showed that maximal stimulation was achieved at 10(-7)M pancreastatin (EC50 = 3 nM). This stimulation was partially inhibited by treatment of the membranes with pertussis toxin. The effect of pancreastatin on guanylate cyclase and phospholipase C were examined by measuring the production of cyclic GMP and myo-inositol 1,4,5-triphosphate respectively. Pancreastatin increased the basal activity of guanylate cyclase to a maximum of 2.5-fold the unstimulated activity at 30 degrees C, in a time- and dose-dependent manner, reaching the maximal stimulation above control with 10(-7) M pancreastatin at 10 min (EC50 = 0.6 nM). This effect was completely abolished when rat liver membranes had been ADP-ribosylated with pertussis toxin. On the other hand, adenylate cyclase activity was not affected by pancreastatin. Phospholipase C activity of rat liver membranes was rapidly stimulated (within 2-5 min) at 30 degrees C by 10(-7) M pancreastatin, reaching a maximum at 15 min.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- V Sánchez-Margalet
- Departmento de Bioquímica Médica y Biología Molecular, Hospital Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Spain
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22
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von Schrenck T, Mackensen B, Mende U, Schmitz W, Sievers J, Mirau S, Raedler A, Greten H. Signal transduction pathway of the muscarinic receptors mediating gallbladder contraction. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1994; 349:346-54. [PMID: 8058106 DOI: 10.1007/bf00170879] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In gallbladder smooth muscle, carbachol interacts with M3 receptors to mediate contraction. To examine components of the intracellular second messenger system that is coupled to these receptors we have tested whether carbachol stimulates the formation of inositol phosphates (IP) to cause contraction. Guinea pig gallbladder muscle strips were prelabeled with [3H]inositol and were incubated with 0.1 mmol/l carbachol, a concentration causing maximal contraction. [3H]inositol monophosphates, [3H]inositol bisphosphates and [3H]inositol trisphosphates and contraction were measured at various times (0-90 s). To examine whether a pertussis toxin-sensitive guanine nucleotide binding protein is coupled to the muscarinic receptors, guinea pigs were pretreated with pertussis toxin (180 micrograms/kg i.v./24 h). The effectiveness of pertussis toxin treatment was determined by measuring [32P]ADP-ribosylation of a approximately 40/41 kDa protein from gallbladder homogenates. Carbachol caused a significant time-dependent increase in the formation of [3H]inositol monophosphates, [3H]inositol bisphosphates and [3H]inositol trisphosphates. The time course of [3H]inositol trisphosphate turnover caused by carbachol was biphasic, and was detectable at 15 s and maximal at 60 s; at 75 s and 90 s formation of [3H]inositol trisphosphates decreased, whereas the time course of carbachol-induced contraction of the gallbladder smooth muscle strips reached a plateau after 90 s. The effects of carbachol on [3H]inositol trisphosphates and on contraction were abolished by atropine.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T von Schrenck
- Medizinische Kernklinik, Universitäts-Krankenhaus Eppendorf, Hamburg, Germany
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23
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Wang CN, Chen JS, Shiao MS, Wang CT. Activation of human platelet phospholipases C and A2 by various oxygenated triterpenes. Eur J Pharmacol 1994; 267:33-42. [PMID: 8206128 DOI: 10.1016/0922-4106(94)90221-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Eight structural analogues of oxygenated triterpenes exerted striking differences in activation of human platelets. They are four pairs of stereoisomers and two pairs of positional isomers with varying: 1) acetoxyl/hydroxyl substituents; 2) the position of the substituents at C-3 and C-15; and 3) the stereochemistry of a substituent at C-3. It required a threshold concentration for each agent to cause the concentration-dependent activation. These triterpenes were hydrophobic with < 20% difference in the partition coefficients between 1-octanol and water. They caused differential effects on: inositol triphosphate production; the increase in [Ca2+]i; diacylglycerol formation; phosphatidic acid accumulation, protein phosphorylations and arachidonate release. These agents activated both phospholipases C and A2. The trend of activating phospholipase C was triterpenes with two acetoxyl substituents > one acetoxyl/one hydroxyl substituents > two hydroxyl substituents. In activating phospholipase A2, triterpenes with two acetoxyl substituents were most effective, whereas the paired isomers with a hydroxyl group at C-15 alpha and an acetoxyl substituent at C-3 failed the activation. The results enable one to discuss the possible structure-activity relationship of various oxygenated triterpenes in the activation of both phospholipases C and A2.
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Affiliation(s)
- C N Wang
- Institute of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC
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24
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Blank JL, Shaw K, Ross AH, Exton JH. Purification of a 110-kDa phosphoinositide phospholipase C that is activated by G-protein beta gamma-subunits. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)74586-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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25
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Tsunoda Y. Receptor-operated Ca2+ signaling and crosstalk in stimulus secretion coupling. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1154:105-56. [PMID: 8218335 DOI: 10.1016/0304-4157(93)90008-c] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In the cells of higher eukaryotic organisms, there are several messenger pathways of intracellular signal transduction, such as the inositol 1,4,5-trisphosphate/Ca2+ signal, voltage-dependent and -independent Ca2+ channels, adenylate cyclase/cyclic adenosine 3',5'-monophosphate, guanylate cyclase/cyclic guanosine 3',5'-monophosphate, diacylglycerol/protein kinase C, and growth factors/tyrosine kinase/tyrosine phosphatase. These pathways are present in different cell types and impinge on each other for the modulation of the cell function. Ca2+ is one of the most ubiquitous intracellular messengers mediating transcellular communication in a wide variety of cell types. Over the last decades it has become clear that the activation of many types of cells is accompanied by an increase in cytosolic free Ca2+ concentration ([Ca2+]i) that is thought to play an important part in the sequence of events occurring during cell activation. The Ca2+ signal can be divided into two categories: receptor- and voltage-operated Ca2+ signal. This review describes and integrates some recent views of receptor-operated Ca2+ signaling and crosstalk in the context of stimulus-secretion coupling.
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Affiliation(s)
- Y Tsunoda
- Department of Faculty Science, Hokkaido University, Sapporo, Japan
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26
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Lu YM, Lu BF, Yan YL, Yan TH, Ho XP, Wang WJ. Alterations of G-protein coupling function in phosphoinositide signalling pathways of rat hippocampus by ischaemic brain injury. Eur J Neurosci 1993; 5:1334-8. [PMID: 7903892 DOI: 10.1111/j.1460-9568.1993.tb00919.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The activation of membrane-associated phospholipase C is rapidly and transiently induced in the central nervous system by a variety of stimuli. Ischaemic brain injury is one of the situations that leads to a dramatic increase in polyphosphoinositide (PPI) turnover. In this study, stimulation of PPI hydrolysis by glutamate (500 microM) was measured in hippocampal slices from rats up to 21 days after an ischaemic insult of 30 min. Ischaemia was induced using the four-vessel occlusion method. PPI hydrolysis elicited by glutamate was significantly increased in the slices prepared from ischaemic rats 24 h after reperfusion, the accumulation of inositol phosphates (InsPs) and inositol 1,4,5-trisphosphate (Insp3) was 614 +/- 74% (n = 8) and 182 +/- 11% (n = 9) of the basal level respectively. This potentiation was also observed 21 days after ischaemia. Hyper-responsiveness to glutamate was also accompanied by an increase in AIF4(-)-stimulated formation of [3H]inositol phosphates. In addition, global ischaemia did not change either high-affinity [3H]glutamate binding in hippocampal membranes or the stimulation of PPI hydrolysis by carbachol or noradrenaline in hippocampal slices. The present results suggest that the increased responsiveness to glutamate is the result, at least in part, of functional changes at the G-protein level, and may contribute to the pathophysiology of ischaemic brain injury or to the regenerative phenomena that accompany ischaemic damage.
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Affiliation(s)
- Y M Lu
- Division of Molecular Pharmacology, Naval Neurobiology Research Centre, Nanjing, China
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27
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Edwards E, Ashby CR, Wang RY. Further characterization of 5-HT- and 5-HT3 receptor agonists'-stimulated phosphoinositol phosphates accumulation. Brain Res 1993; 617:113-9. [PMID: 8397045 DOI: 10.1016/0006-8993(93)90620-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The calcium requirement for serotonin (5-HT)- and the 5-HT3 receptor agonists, 2-Me-5-HT- and PBG-dependent breakdown of phosphatidyl inositol has been examined in the rat fronto-cingulate cortex. The omission of added Ca2+ from the Kreb's incubation medium reduced the [3H]inositol phosphate accumulation from pre-labelled phospholipids. Removal of Ca2+ by pre-incubation with EGTA (0.5 mM), as well as the addition of the calcium channel blocker, lanthanum (10 microM), abolished the 5-HT- and the 5-HT3 receptor agonists'-stimulated phosphoinositide (PI) response. By contrast, the calcium ionophores, A 23187 and Ionomycin (both at 30 microM) stimulated PI hydrolysis, and this effect was additive to the increased PI turnover induced by 5-HT, 2-Me-5-HT and PBG. The increase in phosphoinositide hydrolysis induced by 5-HT and 2-Me-5-HT was significantly inhibited by phorbol dibutyrate (PDBu) and phorbol myristate acetate, indicating that the activation of protein kinase C (PKC) may provide negative feedback to the PI response induced by 5-HT and 2-Me-5-HT-stimulated PI metabolism was reversed by the PKC inhibitors, staurosporine, calphostin C and chelerythrine (all at 10 microM), however, Pertussis toxin (0.5 and 1 microgram) had no effect on either 5-HT's or 2-Me-5-HT's increased stimulation of PI hydrolysis, suggesting that this response is not associated to a Gi GTP binding protein.
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Affiliation(s)
- E Edwards
- Department of Pharmacology and Toxicology, University of Maryland, Baltimore 21201
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28
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Sokolovsky M. Endothelin receptors in rat cerebellum: activation of phosphoinositide hydrolysis is transduced by multiple G-proteins. Cell Signal 1993; 5:473-83. [PMID: 8396963 DOI: 10.1016/0898-6568(93)90087-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Induction of phosphoinositide hydrolysis in rat cerebellar slices by endothelins (ET-1 and ET-3) and sarafotoxins (SRTX-b and SRTX-c) was demonstrated by measurement of labelled inositol phosphate generation. Pertussis toxin (PT) enhanced the induction of phosphoinositide hydrolysis by all four peptides. The process seems to be mediated by at least two heterotrimeric G-proteins, the one sensitive and the other insensitive to PT. Measurement of the GTPase activity induced in this preparation indicated that phosphoinositide hydrolysis is stimulated via a functional coupling between the endothelin receptor of the ETB-R subtype and a PT-insensitive G-protein family, i.e. Gq/11. The involvement of PT-sensitive G-proteins, i.e. Gi-like and/or Go-like proteins, in the stimulation of phosphoinositide hydrolysis by ETs and SRTXs is discussed.
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Affiliation(s)
- M Sokolovsky
- Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel
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29
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Boonen GJ, de Koster BM, VanSteveninck J, Elferink JG. GTP[S] stimulates migration of electropermeabilized neutrophils via a pertussis toxin-sensitive G-protein. Cell Signal 1993; 5:299-304. [PMID: 8347421 DOI: 10.1016/0898-6568(93)90020-m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Electropermeabilized neutrophils were used to study the role of G-proteins in neutrophil migration. Rabbit neutrophils, under specific conditions, retained their ability to migrate after electropermeabilization. Introduction of guanosine-5'-[3-thio] triphosphate (GTP[S]) into the cell interior stimulated random migration and enhanced migration activated by a suboptimal concentration of formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) (10(-11) M). GTP[S] had no effect on random migration by intact cells, or on migration of intact cells activated with a suboptimal concentration of fMet-Leu-Phe, indicating that the effect of GTP[S] was intracellular. The effects of GTP[S] were inhibited by pertussis toxin and by guanosine-5'-[2-thio] diphosphate (GDP beta S) indicating that a pertussis toxin-sensitive G-protein was involved. GTP stimulated random migration to the same extent as GTP[S], but had only a small effect on migration activated by a suboptimal concentration of fMet-Leu-Phe (10(-11) M). Several other nucleotides tested had no effect on random migration or migration activated with 10(-11) M fMet-Leu-Phe. The results show that neutrophil migration can be potentiated by direct activation of a pertussis toxin-sensitive G-protein, and the results obtained with GTP suggest that possibly more than one G-protein is involved in this process.
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Affiliation(s)
- G J Boonen
- Department of Medical Biochemistry, University of Leiden, The Netherlands
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30
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Panfoli I, Morelli A, Viarengo A, Orunesu M. Biochemical characterization of a phosphatidylinositol 4,5-bisphosphate-specific phospholipase C activity in gills and digestive gland of the marine mussel Mytilus galloprovincialis Lam. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1993; 105:139-45. [PMID: 8389267 DOI: 10.1016/0305-0491(93)90180-d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
1. Polyphosphoinositide-specific phosphodiesterase (phospholipase C, PLC) activity against phosphatidylinositol 4,5-bisphosphate, present in gill and digestive gland homogenates of mussel (Mytilus galloprovincialis Lam.), has been biochemically characterized. 2. The enzyme was strictly modulated by free calcium ion concentration in both tissues and maximally activated at 10(-5) M Ca2+ (19 +/- 4 and 11 +/- 2 nmol phosphatidylinositol 4,5-bisphosphate hydrolysed/min/mg of protein for gill and digestive gland PLC, respectively, at 19 degrees C). Optimum pH at 10(-5) M Ca2+ was around 7.0 in both cases. The Ca(2+)-stimulated PLC activity showed high specificity for PIP2; the KMa for PIP2 were 150 and 170 microM for the gills and digestive gland, respectively. 3. Good substrate dispersion was obtained in the presence of sodium deoxycholate; the concentration routinely used in the assay (0.08%) produced a 9-fold activation of both gill and digestive gland PLC, consistent with previous reports. 4. The possible biochemical and physiological role of the enzyme in mussel tissues is discussed.
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Affiliation(s)
- I Panfoli
- Istituto Policattedra di Chimica Biologica dell'Università, Genova, Italy
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31
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Calabresi P, Pisani A, Mercuri NB, Bernardi G. Lithium treatment blocks long-term synaptic depression in the striatum. Neuron 1993; 10:955-62. [PMID: 8494646 DOI: 10.1016/0896-6273(93)90210-i] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have studied the effect of acute and chronic lithium treatment on the activity of striatal neurons recorded from corticostriatal slices. Under control conditions, tetanic stimulation of glutamatergic corticostriatal terminals caused long-term depression (LTD) of excitatory synaptic potentials. Acute lithium treatment did not affect the peak of the induction phase, but it reduced the following phases of LTD. LTD was completely blocked in slices obtained from rats chronically injected with LiCl. Lithium treatment failed to affect the intrinsic membrane properties of striatal neurons and the presynaptic inhibitory effects of carbachol and t-ACPD. We suggest that the lithium-induced blockade of LTD may contribute to the therapeutic action of lithium salts in mania and depression.
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Affiliation(s)
- P Calabresi
- Dipartimento Sanità Università di Roma Tor Vergata, Italy
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32
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Lonart G, Alagarsamy S, Johnson KM. (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors mediate a calcium-dependent inhibition of the metabotropic glutamate receptor-stimulated formation of inositol 1,4,5-trisphosphate. J Neurochem 1993; 60:1739-45. [PMID: 7682601 DOI: 10.1111/j.1471-4159.1993.tb13398.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
L-glutamate (3-1,000 microM) and (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD; 10-1,000 microM), a selective agonist for the metabotropic glutamate receptor, stimulated the formation of inositol 1,4,5-trisphosphate in a concentration-dependent manner. L-Glutamate was half as efficacious as 1S,3R-ACPD. N-methyl-D-aspartate (NMDA; 1 nM to 1 mM) did not significantly influence the response to a maximally effective concentration of 1S,3R-ACPD (100 microM). On the other hand, coapplication of (R,S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA; 1-300 nM) produced a concentration- and time-dependent inhibition of the 1S,3R-ACPD effect, with a maximal inhibition (97%) at 100 nM. Ten micromolar 6-cyano-7-nitroquinoxaline-2,3-dione, an antagonist of the AMPA receptor, blocked the inhibitory effect of AMPA. Reduced extracellular calcium concentration, as well as 10 microM nimodipine, an L-type calcium channel antagonist, inhibited the AMPA influence on the 1S,3R-ACPD response. W-7, a calcium/calmodulin antagonist, prevented the inhibition by AMPA, whereas H-7, an inhibitor of protein kinase C, had no effect. These data suggest that activation of AMPA receptors has an inhibitory influence on inositol 1,4,5-trisphosphate formation mediated by stimulation of the metabotropic glutamate receptor. The mechanism of action involves calcium influx through L-type type calcium channels and possible activation of calcium/calmodulin-dependent enzymes.
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Affiliation(s)
- G Lonart
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston 77555-1031
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33
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Nüsse O, Lindau M. The calcium signal in human neutrophils and its relation to exocytosis investigated by patch-clamp capacitance and Fura-2 measurements. Cell Calcium 1993; 14:255-69. [PMID: 8370063 DOI: 10.1016/0143-4160(93)90047-a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Intracellular calcium ([Ca2+]i) and exocytosis of human neutrophils were investigated with patch-clamp capacitance and Fura-2 fluorescence measurements. Intracellular application of GTP gamma S induces a calcium transient and exocytosis. The onset of degranulation occurs at the time where the maximal [Ca2+]i is reached. Despite the close correlation in time, buffering [Ca2+]i at the resting level or at approximately 2 microM leaves the extent and the time course of degranulation unchanged. The decay of the calcium transient is due to diffusional equilibration between the cytosol and the pipette volume. GTP gamma S activates no cellular mechanisms for Ca2+ reuptake or extrusion. The endogenous calcium buffer capacity can be estimated to be as low as that of approximately 90 microM Fura-2. Stimulation with fMLP also induces degranulation and a calcium transient. The decay of fMLP-induced calcium transients is much faster than that of GTP gamma S-induced transients and is independent of diffusion indicating that fMLP also induces rapid reuptake or extrusion of Ca2+. Degranulation but not the calcium transient requires the presence of intracellular GTP. Different signalling pathways appear to be involved in GTP gamma S- and fMLP-stimulated calcium signals. The intracellular calcium release is not an essential signal to initiate exocytosis in neutrophils.
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Affiliation(s)
- O Nüsse
- Biophysics Group, Freie Universität Berlin, Germany
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34
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Regulation of G protein function by an effector in GTP-dependent signal transduction. An inhibitory subunit of cGMP phosphodiesterase inhibits GTP hydrolysis by transducin in vertebrate rod photoreceptors. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)52958-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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35
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Hara N, Ichinose M, Sawada M, Maeno T. Inositol 1,4,5-trisphosphate mediates adrenaline activation of K+ conductance in mouse peritoneal macrophages. Pflugers Arch 1993; 423:140-8. [PMID: 8387666 DOI: 10.1007/bf00374971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In mouse peritoneal macrophages, alpha 1-adrenoceptor stimulation evokes a Ca(2+)-dependent K+ current [Io(Adr)][Hara et al. (1991) Pflügers Arch 419:371-379]. The roles of D-myo-inositol 1,4,5-trisphosphate (InsP3) and a GTP-binding protein (G protein) in Io(Adr) were investigated with tight-seal whole-cell recordings and fura-2 fluorescence measurements. Intracellular injection of InsP3 (5-50 microM) evoked transient outward currents [Io(InsP3)] with or without damped oscillations in membrane currents at -40 mV. Dialysis with 0.2 mM guanosine 5'-[3-thio]triphosphate (GTP[gamma S], a poorly hydrolysable GTP analogue) at -40 mV activated oscillatory outward currents or a slowly developing steady current on which such oscillations were superimposed after a delay of 10-90 s. Io(InsP3) and the GTP[gamma S]-induced current [Io(GTP[gamma S])] were accompanied by an increase in conductance. Reversal potentials of both responses closely depended on the extracellular K+ concentration. Fura-2 measurements revealed that Io(InsP3) and Io(GTP[gamma S]) result from a rise in intracellular free Ca2+ concentration ([Ca2+]i). Removal of extracellular Ca2+ did not abolish Io(InsP3) and Io(GTP[gamma S]). Both were blocked by bath-applied charybdotoxin. Intracellular D-myo-inositol 1,3,4,5-tetrakisphosphate (InsP4, 50 microM) did not evoke any responses, whereas D-myo-inositol 2,4,5-trisphosphate [InsP3(2,4,5), 20 microM] elicited an outward current at -40 mV. Io(InsP3) was completely blocked by prior dialysis with the InsP3 receptor antagonist heparin (5 mg/ml). Inclusion of guanosine 5'-[2-thiol] diphosphate (GDP[beta S], 2 mM) or heparin (5 mg/ml) together with GTP[gamma S] in the patch pipette solution completely blocked Io(GTP[gamma S]). These results indicate that intracellular injection of InsP3 or GTP[gamma S] mimic Io(Adr).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- N Hara
- Department of Physiology, Shimane Medical University, Izumo, Japan
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36
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37
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Imoto M, Sujikai I, Ui H, Umezawa K. Involvement of tyrosine kinase in growth factor-induced phospholipase C activation in NIH3T3 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1166:188-92. [PMID: 8443236 DOI: 10.1016/0005-2760(93)90096-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Tyrosine kinase inhibitors such as erbstatin and lavendustin derivative inhibited platelet-derived growth factor (PDGF)- and bombesin-induced inositol phosphate formation and phospholipase C (PLC) activation in quiescent NIH3T3 cells. However, bombesin-induced PLC activation was only partially inhibited by tyrosine kinase inhibitors, whereas PDGF-induced activation was completely. Moreover, although bombesin-induced PLC activation was partially inhibited by pertussis toxin alone, this toxin inhibited almost completely in the presence of tyrosine kinase inhibitors. Thus, tyrosine kinase was suggested to be involved in PDGF- and bombesin-induced PLC activation in a different manner.
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Affiliation(s)
- M Imoto
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
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38
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Hackford AW. Biochemical markers for colorectal cancer. Diagnostic and therapeutic implications. Surg Clin North Am 1993; 73:85-102. [PMID: 8426999 DOI: 10.1016/s0039-6109(16)45930-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The development of the understanding of oncogenes, tumor suppressor genes, and signal transduction has provided a significant advance in the concepts of the mechanisms of carcinogenesis in the colon and rectum. The tools provided by the molecular geneticist and the immunobiologist may yield powerful new techniques for screening individuals at risk, for identifying those patients with biologically more aggressive tumors, for developing novel therapies targeted directly at tumor cells, and for providing the means for more sensitive and specific detection of recurrence of disease.
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Affiliation(s)
- A W Hackford
- Department of Surgery, Tufts University School of Medicine, Boston, Massachusetts
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39
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Kim KC, Zheng QX, Van-Seuningen I. Involvement of a signal transduction mechanism in ATP-induced mucin release from cultured airway goblet cells. Am J Respir Cell Mol Biol 1993; 8:121-5. [PMID: 8427704 DOI: 10.1165/ajrcmb/8.2.121] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Release of mucins from cultured airway surface epithelial cells can be stimulated by extracellular ATP via a P2-purinergic receptor-mediated mechanism (K. C. Kim and B. C. Lee. 1991. Br. J. Pharmacol. 103:1053-1056). In this report, we studied the mechanism by which extracellular ATP induces the mucin release. We found that: (1) ATP increased both mucin release and generation of inositol phosphates in a dose-dependent fashion, and their dose-effect relationships were almost superimposed; (2) the increases in both mucin release and the phosphatidylinositol phosphate (PI) turnover by extracellular ATP were partially, but almost equally, blocked by the pretreatment with pertussis toxin (42% for mucin release and 44% for PI turnover). We conclude that in cultured airway goblet cells extracellular ATP stimulates mucin release by a signal transduction mechanism, which seems to involve coupling of ATP-activated P2 purinoceptors with phospholipase C, at least in part, via pertussis toxin-sensitive GTP-binding proteins. This may be an important finding in understanding the regulation of mucin release by airway goblet cells, since a number of agents present in the airway could influence this signal transduction pathway and subsequently modulate the mucin secretion.
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Affiliation(s)
- K C Kim
- Department of Pharmacology and Toxicology, University of Maryland School of Pharmacy, Baltimore, MD 21201
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40
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Kobayashi K, Shaver JK, Liang W, Siperstein AE, Duh QY, Clark OH. Increased phospholipase C activity in neoplastic thyroid membrane. Thyroid 1993; 3:25-9. [PMID: 8388752 DOI: 10.1089/thy.1993.3.25] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The phospholipase C (PLC)-protein kinase C (PKC) signal transduction pathway appears to be important for cellular growth of many normal and neoplastic tissues. Because alterations in the thyroid-stimulating hormone (TSH) receptor-adenylate cyclase-protein kinase A system in some thyroid tumors do not correlate with tumor size, invasiveness, or metastatic potential, we studied the PLC activity in both normal and neoplastic thyroid tissues from 11 patients. Five of these patients had follicular adenomas and 6 had papillary carcinomas. An 8,000 x g membrane fraction and a 105,000 x g cytosol fraction were prepared from the normal and neoplastic human thyroid tissues. PLC hydrolyzes phosphatidylinositol, 4,5-diphosphate (PIP2) to diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP3). Phospholipase C activity was determined measuring the hydrolysis of [3H]-PIP2. The activity of PLC in the neoplastic thyroid tissue membrane fraction (20.91 +/- 2.28 nmol PIP2 hydrolyzed/mg protein/120 min) was higher than that in normal thyroid membrane (14.27 +/- 0.82) (p < 0.05). In contrast, PLC activity was similar in the neoplastic (16.12 +/- 0.86 nmol PIP2 hydrolyzed/mg protein/120 min) and normal (16.66 +/- 0.60) cytosol. There was no difference between PLC activity in the membrane fraction from adenomas (21.21 +/- 3.71 nmol PIP2 hydrolyzed/mg protein/120 min) when compared with thyroid carcinomas (20.67 +/- 3.14). Neoplastic thyroid membranes have greater PLC activity than that found in normal thyroid membranes from the same patients. Although PLC activity in benign and malignant thyroid membranes was similar, the increased PLC activity in thyroid neoplasms may be responsible for or contribute to the enhanced growth of some thyroid tumors.
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Affiliation(s)
- K Kobayashi
- UCSF/Mount Zion Medical Center San Francisco
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Linard C, Reyl-Desmars F, Lewin MJ. Somatostatin inhibition of phosphoinositides turnover in isolated rat acinar pancreatic cells: interaction with bombesin. ACTA ACUST UNITED AC 1992; 41:219-26. [PMID: 1359613 DOI: 10.1016/0167-0115(92)90115-b] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of somatostatin-14 and bombesin on [3H]inositol phosphate accumulation were studied in 24 h myo-[3H]inositol-prelabeled cultured rat acinar cells. Bombesin, 10 nM, stimulated basal formation of phosphatidyl monophosphate (InsP1), phosphatidyl 4,5-biphosphate (InsP2) and inositol 1,4,5-triphosphate (InsP3) by 128 +/- 5.2%, 147 +/- 10% and 155 +/- 5%, respectively. At 5 s, the ED50 value for InsP3 stimulation was 0.70 +/- 0.2 nM. This stimulation was partly blocked (64 +/- 0.04% inhibition) by 10 ng/ml Bordetella pertussis toxin. In contrast to bombesin, somatostatin, 10 nM, inhibited basal InsP1, InsP2 and InsP3 formation. At 5 s, the inhibition degree for InsP3 was 18 +/- 2.5% and the IC50s values 1 +/- 0.09 nM, 1 +/- 0.12 nM and 0.07 +/- 0.005 nM for InsP1, InsP2 and InsP3, respectively. Bombesin-stimulated InsP3 formation was also inhibited by somatostatin. At 5 s, the inhibition degree was 85 +/- 3.5% at 10 nM and the IC50 value, 0.10 +/- 0.05 nM. Furthermore, somatostatin inhibition of bombesin stimulation was partly blocked (66 +/- 4% inhibition) by Bordetella pertussis toxin. These data therefore suggest that the acinar pancreatic cells contain a somatostatin receptor exerting a negative control on basal and bombesin receptor-stimulated phosphatidyl inositol turnover.
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Affiliation(s)
- C Linard
- Unité de recherches de Gastroentérologie (INSERM U10), Hôpital Bichat, Paris, France
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Bacman S, Sterin-Borda L, Gorelik G, Lustig L, Denduchis B, Borda ES. Antilaminin IgG triggers the murine atria phosphoinositide hydrolysis through muscarinic receptor stimulation. INTERNATIONAL JOURNAL OF IMMUNOPHARMACOLOGY 1992; 14:1321-8. [PMID: 1334473 DOI: 10.1016/0192-0561(92)90003-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Induction of polyphosphoinositide hydrolysis in cardiac tissue by specific recognition of laminin by antilaminin IgG was assayed. BALB/c mice atria were labelled with the myo-[3H]-inositol precursor and inositol phosphate production was measured in the presence and absence of antilaminin and normal IgG. Antilaminin IgG but not normal IgG specifically increased phosphoinositide (PI) turnover. This increment was blocked by the muscarinic cholinergic antagonist atropine and mimicked by the cholinergic agonist carbachol. The phospholipase C inhibitor diphenylcarbamate (NCDC) also antagonized the stimulatory action of antilaminin IgG on PI turnover. By using an immunofluorescence technique, antilaminin IgG reacted with myocardial cell basement membranes. This antibody fixation was not blocked by atropine. These data suggest that antilaminin IgG specifically recognized myocardial laminin molecules and activated PI turnover through cholinergic stimulation. Even though laminin and cholinergic receptors are different, they probably share common signal transduction systems.
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Affiliation(s)
- S Bacman
- Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Argentina
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43
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Tertrin-Clary C, De La Llosa-Hermier MP, Roy M, Chenut MC, Hermier C, De La Llosa P. Activation of phospholipase C by different effectors in rat placental cells. Cell Signal 1992; 4:727-36. [PMID: 1489662 DOI: 10.1016/0898-6568(92)90054-c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present communication documents the accumulation of inositol phosphates in rat placental cells by fluoride as well as by vanadate. These findings suggest the existence of the phosphoinositide pathway and its modulation by a G-protein. A concomitant action of fluoride on phosphoinositide breakdown was also observed. As is often the case in intact cells from different organs, protein kinase C exerts a feedback regulatory control on this signalling system. Gonadotropin-releasing hormone (GnRH) also stimulated the accumulation of inositol phosphates in cultured cells but no effect could be detected in freshly isolated cells. Therefore, the phosphoinositide pathway seems to be involved in the mechanism of action of GnRH in rat placental cells.
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45
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Mirossay L, Di Gioia Y, Chastre E, Emami S, Gespach C. Pharmacological control of gastric acid secretion: Molecular and cellular aspects. Biosci Rep 1992; 12:319-68. [PMID: 1363275 DOI: 10.1007/bf01121499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- L Mirossay
- Institut National de la Santé et de la Recherche Médicale INSERM U. 55, Unité de Recherches sur les Peptides Neurodigestifs et le Diabète, Hôpital Saint-Antoine, Paris, France
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46
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Sontag JM, Aunis D, Bader MF. Two GTP-binding Proteins Control Calcium-dependent Exocytosis in Chromaffin Cells. Eur J Neurosci 1992; 4:98-101. [PMID: 12106445 DOI: 10.1111/j.1460-9568.1992.tb00112.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of guanosine triphosphate analogues on catecholamine secretion from permeabilized bovine chromaffin cells was examined. Guanosine 5'-[gamma-thio]triphosphate was demonstrated to produce a dual effect on calcium-evoked secretion, enhancing the release through a mechanism involving protein kinase C and inhibiting secretion by a protein kinase C-independent pathway. We propose that two functionally distinct G-proteins control the stimulus - secretion coupling in chromaffin cells.
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Affiliation(s)
- Jean-Marie Sontag
- Unité INSERM U-338 Biologie de la Communication Cellulaire, 5, rue Blaise Pascal, 67084 Strasbourg Cédex, France
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47
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Heterogeneity of the retinal G-protein transducin from frog rod photoreceptors. Biochemical identification and characterization of new subunits. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41803-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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48
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Cockroft S. C-protein-regulated phospholipases C, D and A2-mediated signalling in neutrophils. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0304-4157(92)90036-a] [Citation(s) in RCA: 192] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Gerwins P, Fredholm B. ATP and its metabolite adenosine act synergistically to mobilize intracellular calcium via the formation of inositol 1,4,5-trisphosphate in a smooth muscle cell line. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41969-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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50
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Ilincheta de Boschero MG, Giusto NM. Phosphatidic acid and polyphosphoinositide metabolism in rod outer segments. Differential role of soluble and peripheral proteins. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1127:105-15. [PMID: 1322705 DOI: 10.1016/0005-2760(92)90265-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The phosphorylation of endogenous diacylglycerol (DAG) and phosphoinositides by [tau-32P]ATP was studied in bovine rod outer segments (ROS) selectively depleted of soluble or peripheral and soluble proteins by treatment with moderate (100 mM) or low (5 mM) ionic strength medium, respectively. DAG kinase activity was similar in bleached and non-bleached ROS extracted with 100 mM medium, and amounted to 70% of that observed in the corresponding non-extracted ROS. Phosphatidic acid (PtdH) labelling in ROS extracted in the dark with low ionic strength medium was markedly lower than in those extracted in light. Thus, even when a major proportion of DAG kinase was associated to the membrane, a soluble form also occurred. Most of the membrane-bound fraction behaved as a peripherally associated protein, its binding to the membrane being modified by light. Ir ROS extracted at moderate ionic strength the labelling of inositides was similar to that in non-extracted ROS. A marked enhancement in polyphosphoinositide labelling was observed in ROS extracted in the dark with low ionic strength. Alkaline treatment of ROS also produced inhibition of polyphosphoinositide phosphorylation. A peripheral form of a type C phospholipase, or a peripheral protein-mediated activation of a particulate form thereof, is suggested. Labelled polyphosphoinositides were more actively hydrolyzed in the light and in the dark plus GTP tau S than in the dark-incubated membranes. The results of phosphorylation experiments in membranes where differential extraction of the alpha subunit of transducin was carried out suggest that alpha and beta tau subunits may play opposite modulating roles in PtdH and polyphosphoinositide metabolism.
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Affiliation(s)
- M G Ilincheta de Boschero
- Instituto de Investigaciones Bioquímicas, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Bahía Blanca, Argentina
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