151
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Nahorski SR, Jenkinson S, Challiss RA. Lithium-induced disruption of cell signalling in brain: evidence implicating the phosphoinositide cycle. PHARMACOLOGY & TOXICOLOGY 1992; 71 Suppl 1:42-8. [PMID: 1336197 DOI: 10.1111/j.1600-0773.1992.tb01628.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S R Nahorski
- Department of Pharmacology and Therapeutics, University of Leicester, Leicester, U.K
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152
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Bothmer J, Markerink M, Jolles J. Brain phosphatidic acid and polyphosphoinositide formation in a broken cell preparation: regional distribution and the effect of age. Neurochem Int 1992; 21:223-8. [PMID: 1338899 DOI: 10.1016/0197-0186(92)90151-g] [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: 12/26/2022]
Abstract
The effect of age on phosphate incorporation into phosphatidylinositol 4-phosphate (PIP), phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidic acid (PA) was studied. Lysed crude synaptosomal fractions of different brain regions of 3-month-old and 32-month-old Brown Norway rats were used. The brain regions tested were the hippocampus, frontal cortex, occipital/parietal cortex, entorhinal/pyriformal cortex, striatum/septum, thalamus and hypothalamus. The individual specific phosphorylating activities were unevenly distributed within the brain of Brown Norway rats. Strikingly, the distribution of phosphate incorporation into PIP2 was opposite from that of phosphate incorporation into PA. Phosphate incorporation into PA decreased (-15%) with age in almost all brain regions tested, whereas phosphate incorporation into PIP2 decreased with age only in the frontal cortex (-20%) and in the hypothalamus (-8%). The effects of age may reflect a deterioration of phosphoinositide metabolism, with its function in signal transduction coupled to receptors via G-proteins, in the brain regions involved. In addition, there was an age related decrease in protein content and total phospholipid phosphorus content of lysed crude synaptosomal preparations of all brain regions. The high correlation between the changes in these parameters may be indicative of a decrease in the number or size of synaptosomes with age in the brain regions involved.
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Affiliation(s)
- J Bothmer
- Department of Neuropsychology and Psychobiology, University of Limburg, Maastricht, The Netherlands
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153
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MacPhee CH. Granulocyte/macrophage colony-stimulating factor affects myo-inositol metabolism in a novel manner. Implications for its priming action on human neutrophils. Biochem J 1992; 286 ( Pt 2):535-40. [PMID: 1530586 PMCID: PMC1132930 DOI: 10.1042/bj2860535] [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: 12/27/2022]
Abstract
Little is known about the signal transduction processes involved in the priming action of granulocyte/macrophage colony-stimulating factor (GM-CSF) on neutrophils. This study has used myo-[3H]inositol-labelled human neutrophils to determine whether preincubation with GM-CSF influences myo-inositol (Ins) metabolism in control cells, or in cells stimulated with the bacterial chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMetLeuPhe). GM-CSF pretreatment did not influence the total cellular 3H radioactivity content, demonstrating that the cytokine had no effect on Ins uptake. However, neutrophils pretreated with GM-CSF showed a dramatic 25-40% fall in the free [3H]Ins content of the cell, which was almost quantitatively recovered in a 2-4-fold increase in radioactivity within PtdIns. The remainder of the 3H radioactivity was found proportionately distributed throughout all other [3H]Ins-containing metabolites. Interestingly, in comparison with controls, the GM-CSF-stimulated increases in [3H]polyphosphoinositide (including 3-phosphorylated lipids) and [3H]Ins polyphosphate contents were consistently higher than that observed with PtdIns. This observation suggests that GM-CSF influences the hormone-sensitive pool of PtdIns, possibly through the activation of a PtdIns synthase which is rate-limiting to subsequent metabolic pathways. This is the first report of an action of GM-CSF on Ins metabolism, and highlights the conversion of Ins to PtdIns as a key regulatory metabolic step.
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Affiliation(s)
- C H MacPhee
- SmithKline Beecham Pharmaceuticals, Welwyn, Herts, U.K
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154
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Wong NS, Barker CJ, Morris AJ, Craxton A, Kirk CJ, Michell RH. The inositol phosphates in WRK1 rat mammary tumour cells. Biochem J 1992; 286 ( Pt 2):459-68. [PMID: 1530577 PMCID: PMC1132920 DOI: 10.1042/bj2860459] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. A detailed structural survey has been made of the inositol phosphates of unstimulated and vasopressin-stimulated WRK-1 rat mammary tumour cells. Inositol phosphate peaks were separated by h.p.l.c., and structural assignments were made for more than 20 compounds by combinations of: (a) co-chromatography with labelled standards; (b) site-specific enzymic dephosphorylation; (c) complete and partial periodate oxidation, followed by h.p.l.c. of polyols and their stereospecific oxidation by dehydrogenases; and (d) ammoniacal hydrolysis. 2. The 'inositol monophosphates' fraction from unstimulated cells included an uncharacterized peak, probably containing some glycerophosphoinositol, and Ins(1:2-cyclic)P. Stimulation provoked accumulation of both Ins1P and Ins3P, of Ins2P, and of Ins5P and/or the enantiomers Ins4P and Ins6P. The proportions of Ins1P and Ins3P were determined by partial periodate oxidation and enantiomeric identification of the resulting glucitols. 3. Three inositol bisphosphate peaks were detected in unstimulated cells: Ins(1,4)P2 [this was distinguished chemically from its enantiomer Ins(3,6)P2], Ins(3,4)P2 and/or Ins(1,6)P2, and Ins(4,5)P2 and/or Ins(5,6)P2. On stimulation, Ins(1,4)P2 and Ins(3,4)P2 [and/or Ins(1,6)P2] levels increased, and Ins(1:2-cyclic,4)P2 and Ins(1,3)P2 were also formed. 4. Three inositol trisphosphate peaks were obtained from unstimulated cells: all increased during stimulation. These were Ins(1,3,4)P3 [with some Ins(1:2-cyclic,4,5)P3], Ins(1,4,5)P3 and Ins(3,4,5)P3 [and/or Ins(1,5,6)P3]. During stimulation, another compound, probably Ins(1,4,6)P3, appeared in the 'Ins(1,4,5)P3 peak'. The 'Ins(3,4,5)P3 peak' contained a second trisphosphate, probably Ins(2,4,5)P3. 5. Three inositol tetrakisphosphates, namely Ins(1,3,4,6)P4, Ins(1,3,4,5)P4, were present in unstimulated cells, and all accumulated during stimulation. 6. Ins(1,3,4,5,6)P5, which is the most abundant inositol polyphosphate in these cells, a less abundant inositol pentakisphosphate and inositol hexakisphosphate were all unresponsive to stimulation.
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Affiliation(s)
- N S Wong
- School of Biochemistry, University of Birmingham, U.K
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155
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Desai T, Gigg J, Gigg R, Payne S, Penades S, Rogers HJ. The allylation of dibutylstannylene derivatives of myo -inositol. Carbohydr Res 1992. [DOI: 10.1016/0008-6215(92)84162-l] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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156
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Hiles ID, Otsu M, Volinia S, Fry MJ, Gout I, Dhand R, Panayotou G, Ruiz-Larrea F, Thompson A, Totty NF. Phosphatidylinositol 3-kinase: structure and expression of the 110 kd catalytic subunit. Cell 1992; 70:419-29. [PMID: 1322797 DOI: 10.1016/0092-8674(92)90166-a] [Citation(s) in RCA: 534] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Purified bovine brain phosphatidylinositol 3-kinase (Pl3-kinase) is composed of 85 kd and 110 kd subunits. The 85 kd subunit (p85 alpha) lacks Pl3-kinase activity and acts as an adaptor, coupling the 110 kd subunit (p110) to activated protein tyrosine kinases. Here the characterization of the p110 subunit is presented. cDNA cloning reveals p110 to be a 1068 aa protein related to Vps34p, a S. cerevisiae protein involved in the sorting of proteins to the vacuole. p110 expressed in insect cells possesses Pl3-kinase activity and associates with p85 alpha into an active p85 alpha-p110 complex that binds the activated colony-stimulating factor 1 receptor. p110 expressed in COS-1 cells is catalytically active only when complexed with p85 alpha.
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Affiliation(s)
- I D Hiles
- Ludwig Institute for Cancer Research, London, England
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157
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Nickels JT, Buxeda R, Carman G. Purification, characterization, and kinetic analysis of a 55-kDa form of phosphatidylinositol 4-kinase from Saccharomyces cerevisiae. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42000-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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158
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Aukema HM, Chapkin RS, Tomobe K, Takahashi H, Holub BJ. In vivo formation of polyphosphoinositide isomers and association with progression of murine polycystic kidney disease. Exp Mol Pathol 1992; 57:39-46. [PMID: 1327862 DOI: 10.1016/0014-4800(92)90047-f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Polyphosphoinositide isomers have been demonstrated to be important mediators of cell proliferation in vitro. The present study demonstrates, for the first time, the in vivo formation of the novel isomer, phosphatidylinositol(3)phosphate, in the kidney and liver of intact animals following intraperitoneal administration of [3H]myo-inositol. The formation of renal [3H]phosphatidylinositol(3)phosphate relative to total [3H]phosphatidylinositol-phosphate was positively correlated with cyst proliferation and renal enlargement in a murine model of polycystic kidney disease. Furthermore, despite no difference in the formation of renal [3H]phosphatidylinositol(4)phosphate, a markedly lower accumulation (by 48%) of [3H]phosphatidylinositol(4,5)bisphosphate was observed in the diseased animals as compared to controls. These results indicate that further studies on the in vivo formation of specific polyphosphoinositide isomers in disease states characterized by abnormal growth and oncogene expression are warranted.
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Affiliation(s)
- H M Aukema
- Department of Nutritional Sciences, University of Guelph, Ontario, Canada
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159
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Freund WD, Mayr GW, Tietz C, Schultz JE. Metabolism of inositol phosphates in the protozoan Paramecium. Characterization of a novel inositol-hexakisphosphate-dephosphorylating enzyme. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:359-67. [PMID: 1628659 DOI: 10.1111/j.1432-1033.1992.tb17058.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Basal and stimulated levels of inositol phosphates were determined in the protozoan Paramecium labelled with myo-[3H]inositol. Under resting conditions, intracellular InsP6 (phytic acid), InsP5 and InsP4 concentrations were 140, 10 and 2 microM, respectively. InsP5 was comprised of 56% Ins(1,2,3,4,5)P5 and/or Ins(1,2,3,5,6)P5, 40% Ins(1,2,4,5,6)P5 and/or Ins(2,3,4,5,6)P5 and small amounts of Ins(1,3,4,5,6)P5 and Ins(1,2,3,4,6)P5. InsP4 was mainly Ins(1, 4, 5, 6)P4 and/or Ins(3, 4, 5, 6)P4. Other inositol phosphates were not detected at a detection limit of 50-85 nM. Using various depolarizing and hyperpolarizing stimuli, no significant changes in level of inositol phosphates were observed in vivo, indicating that in the ciliate a contribution of inositol phosphates to signal-transduction mechanisms is unlikely. In homogenates prepared from myo-[3H]inositol-labelled cells, a marked relative increase in InsP3 and InsP4 over the concentrations in vivo was observed. These inositol phosphates were identified as degradation products of endogenous InsP6. A novel separation methodology for inositol phosphates was established to allow unequivocal assignment of phosphate locations of all dephosphorylated InsP6-derived products. The dephosphorylation was catalyzed by a phytase-like enzyme with a molecular mass of 240 kDa, most likely of a hexameric structure. The enzyme had a pH optimum of 7.0 and did not require divalent cations for activity. Substrate concentrations above 300 microM were inhibitory. Dephosphorylation of InsP6 by the Paramecium enzyme differs from that of phytases from plants in that it proceeds via a sequential release of phosphate groups from positions 6, 5, 4 and 3 of the myo-inositol ring or/and positions 4, 5, 6 and 1.
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Affiliation(s)
- W D Freund
- Pharmazeutisches Institut, Universitat Tübingen, Federal Republic of Germany
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160
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Abstract
Phosphatidylinositol (PI) kinase and PI phosphate (PIP) kinase activities were measured in postmortem samples of brain tissue from patients with Alzheimer's disease and nondemented control subjects. A membrane-free cytosolic fraction from four neocortical locations, with exogenous inositol lipids as the substrate, was used. Tissue from patients with Alzheimer's disease was characterized by reduced PIP formation; the reduction was 50% in prefrontal cortex, temporal cortex, and parietal cortex and 40% in precentral gyrus. In contrast, no alterations were found in PI bisphosphate formation in these four neocortical locations. The specific changes in PI kinase but not PIP kinase activity suggest that the findings may have functional relevance to the involvement of brain membrane processes in Alzheimer's disease.
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Affiliation(s)
- J Jolles
- Department of Neuropsychology and Psychobiology, University of Limburg, Maastricht, The Netherlands
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161
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Claro E, Wallace MA, Fain JN. Concerted CMP-dependent [3H]inositol labeling of phosphoinositides and agonist activation of phospholipase C in rat brain cortical membranes. J Neurochem 1992; 58:2155-61. [PMID: 1315377 DOI: 10.1111/j.1471-4159.1992.tb10958.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
[3H]Inositol ([3H]Ins) labeling of phosphoinositides was studied in rat brain cortical membranes. [3H]Ins was incorporated into a common lipid pool through both CMP-dependent and independent mechanisms. These are as follows: (1) a reverse reaction catalyzed by phosphatidyl-inositol (PtdIns) synthase, and (2) the reaction performed by the PtdIns headgroup exchange enzyme, respectively. Membrane phosphoinositides prelabeled in either CMP-dependent or independent fashions were hydrolyzed by guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S)- and carbachol-stimulated phospholipase C. Unlike CMP-dependent labeling, however, CMP-independent incorporation of [3H]Ins into lipids was inhibited by 1 mM (0.04%) sodium deoxycholate. Thus, when PtdIns labeling and phospholipase C stimulation were studied in a concerted fashion, [3H]Ins was incorporated into lipids primarily through the PtdIns synthase-catalyzed reaction because of the presence of deoxycholate required to observe carbachol-stimulation of phospholipase C. Little direct breakdown of [3H]PtdIns was detected because production of myo-[3H]inositol 1-monophosphate was minimal and myo-[3H]inositol 1,4-bisphosphate was the predominant product. Although PtdIns labeling and 3H-polyphosphoinositide formation were unaffected by GTP gamma S and carbachol and had no or little lag period, GTP gamma S- and carbachol-stimulated appearance of 3H-Ins phosphates exhibited an appreciable lag (10 min). Also, flux of label from [3H]Ins to 3H-Ins phosphates was restricted to a narrow range of free calcium concentrations (10-300 nM). These results show the concerted activities of PtdIns synthase, PtdIns 4-kinase, and phospholipase C, and constitute a simple assay for guanine nucleotide-dependent agonist stimulation of phospholipase C in a brain membrane system using [3H]Ins as labeled precursor.
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Affiliation(s)
- E Claro
- Department of Biochemistry, University of Tennessee, Memphis
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162
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Macphee C, Carter A, Ruiz-Larrea F, Ward J, Young R, Downes C. The stereoselective recognition of substrates by phosphoinositide kinases. Studies using synthetic stereoisomers of dipalmitoyl phosphatidylinositol. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)49886-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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163
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Sasakawa N, Nakaki T, Kashima R, Kanba S, Kato R. Stimulus-induced accumulation of inositol tetrakis-, pentakis-, and hexakisphosphates in N1E-115 neuroblastoma cells. J Neurochem 1992; 58:2116-23. [PMID: 1573394 DOI: 10.1111/j.1471-4159.1992.tb10953.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
When [3H]inositol-prelabelled N1E-115 cells were stimulated with carbamylcholine (CCh) (100 microM), high K+ (60 mM), and prostaglandin E1 (PGE1) (10 microM), a transient increase in [3H]inositol pentakisphosphate (InsP5) accumulation was observed. The accumulation reached its maximum level at 15 s and had declined to the basal level at 2 min. CCh, high K+, and PGE1 also caused accumulations of [3H]inositol 1,4,5-trisphosphate [Ins(1,4,5)P3], [3H]inositol 1,3,4,6-tetrakisphosphate [Ins(1,3,4,6)P4], and [3H]inositol hexakisphosphate (InsP6). Muscarine and CCh induced accumulations of [3H]Ins(1,4,5)P3, [3H]-Ins(1,3,4,6)P4, [3H]InsP5, and [3H]InsP6 with a similar potency and exerted these maximal effects at 100 microM, whereas nicotine failed to do so at 1 mM. With a slower time course, CCh, high K+, and PGE1 caused accumulations of [3H]-inositol 1,3,4-trisphosphate [Ins(1,3,4)P3] and [3H]inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4]. In an N1E-115 cell homogenate, [3H]Ins(1,4,5)P3, [3H]Ins(1,3,4,5)P4, and [3H]Ins(1,3,4)P3 were converted to [3H]InsP5 through [3H]-Ins(1,3,4,6)P4. The above results indicate that Ins(1,3,4,6)P4, InsP5, and InsP6 are rapidly formed by several kinds of stimulants in N1E-115 cells.
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Affiliation(s)
- N Sasakawa
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
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164
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Ohkuma S, Kishi M, Ma FH, Kuriyama K. Association of functional alteration in intracellular signal transduction systems with the occurrence of up-regulation of muscarinic receptors in primary cultured neurons. Prog Neuropsychopharmacol Biol Psychiatry 1992; 16:413-24. [PMID: 1589594 DOI: 10.1016/0278-5846(92)90092-s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. Alterations in intracellular biosignaling systems associated with the up-regulated muscarinic receptor were investigated using primary cultured neurons exposured to 10 nM atropine for 5 days. 2. In neurons treated with atropine, the response of PI turnover to muscarinic stimulation decreased in comparison with that in non-treated neurons. 3. The GTP gamma S-stimulated PI turnover also reduced in neurons possessing up-regulated muscarinic receptor, although phospholipase C activity was not different in these two types of neurons. 4. In addition, the long-term exposure (5 days) to atropine induced the increase in GTPase activity and [3H]GppNHp binding. 5. These results suggest that the decreased response of PI turnover to muscarinic stimulation may be attributed to the functional deterioration of G-protein itself and/or coupling between G-protein and phospholipase C. 6. The present results also strongly suggest that the accentuation of the function of G protein may occur in association with the up-regulation of muscarinic receptor.
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Affiliation(s)
- S Ohkuma
- Department of Pharmacology, Kyoto Prefectural University of Medicine, Japan
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165
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Bunce CM, French PJ, Patton WN, Turnell AS, Scott SA, Michell RH, Kirk CJ, Brown G. Levels of inositol metabolites within normal myeloid blast cells and changes during their differentiation towards monocytes. Proc Biol Sci 1992; 247:27-33. [PMID: 1348118 DOI: 10.1098/rspb.1992.0005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A homogeneous population of undifferentiated myeloid blast cells was purified from human fetal liver by rosette sedimentation of erythroblasts and macrophages, after coating these cells with monoclonal antibodies, followed by a cell elutriation step. The undifferentiated blast cells were maintained in culture, in a serum-free medium containing 1 mg l-1 inositol, by the presence of a high concentration of interleukin-3 (100 U ml-1). This allowed equilibrium labelling of cells with [2-3H]myo-inositol and analysis of the concentrations of inositol metabolites. The myeloid blast cells contained high concentrations of an unidentified inositol metabolite, possibly sn-glycero-3-phospho-1-inositol (GroPIns, 22 microM), inositol monophosphate (InsP, 16 microM), an unidentified inositol bisphosphate (InsP2, 9.4 microM), inositol pentakisphosphate (InsP5, 37 microM) and inositol hexakisphosphate (InsP6, 31 microM). These high concentrations are similar to those reported in the promyeloid cell line, HL60. Treatment of the blast cells with 10 nM phorbol myristate acetate (PMA) resulted in rapid differentiation of 48% of the cells towards monocytes. Notable changes in the levels of inositol metabolites included an increase in the putative GroPIns peak (to 73 microM) and decreases in the concentrations of InsP4 (from 4 microM to 1 microM) and InsP5 (to 21 microM). These changes in response to PMA, with the exception of the rise in the putative GroPIns, are similar to those reported in HL60 cells undergoing monocyte differentiation. These observations suggest that the abundant inositol polyphosphates may have an as yet unknown role in myeloid differentiation.
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Affiliation(s)
- C M Bunce
- Department of Immunology, University of Birmingham, Edgbaston, U.K
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166
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Klein G, Martin JB, Cotter DA, Satre M. Multinuclear NMR spectroscopy of the cellular slime mold Polysphondylium pallidum. Monitoring of the encystment and excystment processes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 204:847-56. [PMID: 1541296 DOI: 10.1111/j.1432-1033.1992.tb16704.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Polysphondylium pallidum microcysts and amoebae have been investigated by 31P- and natural-abundance proton-decoupled 13C-NMR spectroscopy. Microcysts have been found to contain as prominent metabolites a phosphomonoester, inositol hexakisphosphate (1.4 mM), two phosphodiesters [glycerophosphocholine (5.5 mM) and glycerophosphoethanolamine (2.6 mM)], as well as nucleoside triphosphates (3 mM) and polyphosphates (greater than 10 mM), the polyamines 1,3-diamino-propane (3.5 mM), putrescine (16 mM) and spermidine (3 mM) and the sugar trehalose (31 mM). In vivo 31P-NMR has shown that the level of nucleoside triphosphates in microcysts was maintained metabolically and that the pH of their cytosol, deduced from the chemical shift of cytosolic Pi was 7.2. The absence of trehalose, glycerophosphocholine and glycerophosphoethanolamine in P. pallidum amoebae was the most remarkable difference from microcysts. Microcyst germination (excystment), induced by reduction of the ionic strength of the microcyst bathing medium, was monitored non-invasively by 31P- and 13C-NMR spectroscopy. The major modifications observed during excystment were the progressive disappearance of trehalose used as energy source, of glycerophosphocholine and glycerophosphoethanolamine used as membrane phospholipid precursors, and, finally, the appearance of NMR-visible polyphosphates and of cellobiose. As a mirror situation, P. pallidum amoebae responded to a high-ionic-strength stress by production of trehalose, glycerophosphocholine, and glycerophosphoethanolamine, and induction of an encystment process.
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Affiliation(s)
- G Klein
- Département de Biologie Moléculaire et Structurale/Laboratoire de Biologie Cellulaire, Centre d'Etudes Nucléaires de Grenoble, France
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167
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168
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Fisher SK, Heacock AM, Agranoff BW. Inositol lipids and signal transduction in the nervous system: an update. J Neurochem 1992; 58:18-38. [PMID: 1309233 DOI: 10.1111/j.1471-4159.1992.tb09273.x] [Citation(s) in RCA: 194] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S K Fisher
- Department of Pharmacology, University of Michigan, Ann Arbor 48104-1687
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169
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Fang WG, Pirnia F, Bang YJ, Myers CE, Trepel JB. P2-purinergic receptor agonists inhibit the growth of androgen-independent prostate carcinoma cells. J Clin Invest 1992; 89:191-6. [PMID: 1309535 PMCID: PMC442836 DOI: 10.1172/jci115562] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
To develop a new approach to the treatment of advanced, hormone-refractory prostate cancer, the signal transductions regulating the growth of human androgen-independent prostate carcinoma cell lines were studied. Agonist-stimulated Ca2+ mobilization, a critical regulatory event in other secretory cell types, was studied as a means of identifying previously undescribed plasma membrane receptors that may transduce a growth inhibitory signal. In all of the cell lines tested, P2-purinergic receptor agonists, including ATP and certain hydrolysis-resistant adenine nucleotides, induced a rapid, transient increase in cytoplasmic free Ca2+ that was detectable at 50 to 100 nM ATP, was maximal at 100 microM ATP, and was inhibited approximately 50% by chelation of extracellular Ca2+. Within 8 s after addition, ATP stimulated accumulation of the polyphosphatidylinositol products inositol (1, 4, 5) trisphosphate, inositol (1, 3, 4) trisphosphate, and inositol tetrakisphosphate. In addition to stimulating phosphatidylinositol turnover and Ca2+ mobilization, ATP and hydrolysis-resistant ATP analogues induced greater than 90% inhibition of the growth of all lines tested. These data demonstrate that human androgen-independent prostate carcinoma cells express functional P2-purinergic receptors linked to phospholipase C, and that agonists of this receptor are markedly growth inhibitory, suggesting a novel therapeutic approach to this common adult neoplasm.
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Affiliation(s)
- W G Fang
- Clinical Pharmacology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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170
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Borg B, De Renzis G, Payan P, Ciapa B. Activation of polyphosphoinositide metabolism at artificial maturation of Patella vulgata oocytes. Dev Biol 1992; 149:206-12. [PMID: 1309456 DOI: 10.1016/0012-1606(92)90277-n] [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: 12/26/2022]
Abstract
The metabolism of polyphosphoinositides (PPI) has been investigated during the meiosis reinitiation of the oocytes of a prosobranch mollusk, the limpet Patella vulgata. Meiosis reinitiation which leads to germinal vesicle breakdown (GVBD) and metaphase-1 spindle formation was artificially induced by treating the prophase-blocked oocytes with 10 mM NH4Cl, pH 8.2. This treatment, which results in a rise in intracellular pH, triggered a general increase in polyphosphoinositide synthesis. Determinations of phosphorus content showed that maturation induced a 30 to 50% increase in both phosphatidylinositol (PI) and phosphatidylinositol-1 monophosphate (PIP) concentrations. Incorporations of 32PO4 and [3H]inositol have been measured in three classes of polyphosphoinositides: PI, PIP, and phosphatidylinositol 4,5-bisphosphate (PIP2). By comparing incorporation rates of the radiolabeled precursors into PPI before and after meiosis reinitiation, we found that artificial maturation by ammonia induced a 50-fold increase in the turnover of these lipids. No significant burst of inositol 1,4,5-trisphosphate (IP3) was observed after maturation. We suggest that modifications in PPI metabolism occurring at maturation of Patella oocytes might ensure the formation of an important stock of PPI that would be available for the profuse production of IP3, the messenger responsible for the Ca2+ signal at fertilization.
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Affiliation(s)
- B Borg
- Laboratoire de Physiologie Cellulaire et Comparée, CNRS URA 651, Université de Nice, France
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171
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Kurian P, Chandler LJ, Patel R, Crews FT. Receptor coupling to phosphoinositide signals. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1992; 318:399-411. [PMID: 1322027 DOI: 10.1007/978-1-4615-3426-6_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- P Kurian
- University of Florida College of Medicine, Department of Pharmacology, Gainesville 32610
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172
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Moolenaar WH, Jalink K, van Corven EJ. Lysophosphatidic acid: a bioactive phospholipid with growth factor-like properties. Rev Physiol Biochem Pharmacol 1992; 119:47-65. [PMID: 1604155 DOI: 10.1007/3540551921_3] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- W H Moolenaar
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, Amsterdam
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173
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Cocco L, Martelli AM, Gilmour RS, Rana RA, Barnabei O, Manzoli FA. Changes in inositol lipid metabolism and protein kinase C translocation in nuclei of mitogen stimulated Swiss 3T3 cells. ADVANCES IN ENZYME REGULATION 1992; 32:91-103. [PMID: 1323206 DOI: 10.1016/0065-2571(92)90010-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The correlation between changes in nuclear polyphosphoinositide levels preceding PKC translocation to the nucleus and the onset of DNA synthesis has been discussed. Using two different clones of Swiss 3T3 fibroblasts belonging to the same original cell line, one of which is unresponsive to mitogenic stimulation with IGF-I on its own or in combination with bombesin, it has been observed that a rapid and transient breakdown of nuclear PIP and PIP2 occurs only in responsive cells and this precedes the translocation of PKC to the nucleus, as evidenced by immunochemical analysis as well as by enzymatic activity. Therefore, it seems that a direct link exists between nuclear polyphosphoinositide metabolism, PKC translocation to the nucleus and cell division. Since IGF-I acts at the plasma membrane through a tyrosine kinase receptor it seems that the mitogenic stimulation induced by this factor utilizes different signalling pathways at the plasma membrane and at the nucleus. Because of the evidence that type I IGF receptor is expressed in both responsive and unresponsive cells and that the receptor machinery at the plasma membrane is active the lack of the transient changes in nuclear inositol lipids and of PKC translocation in unresponsive cells further suggests that the cell nucleus is capable of an autonomous signalling system based on polyphosphoinositide metabolism.
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Affiliation(s)
- L Cocco
- Institute of Human Anatomy, University of Bologna, Italy
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174
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Fruen BR, Lester BR. Inositol and inositol 1,4,5-trisphosphate content of Down syndrome fibroblasts exhibiting enhanced inositol uptake. FEBS Lett 1991; 295:43-7. [PMID: 1837274 DOI: 10.1016/0014-5793(91)81380-q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fibroblasts from individuals with Down syndrome (DS; trisomy 21) exhibit increased inositol uptake. Here we examine the relationship between this increase in uptake and mass levels of free inositol and inositol 1,4,5-trisphosphate (IP3) in DS fibroblasts. We report that human fibroblasts contain high levels of free inositol which are not significantly affected by the increase in inositol uptake associated with DS. In addition, increased uptake is accompanied by increased efflux of radiolabelled inositol from DS cells. Neither basal nor bradykinin-stimulated IP3 levels in DS cells differ significantly from normal values. This work highlights the usefulness of the DS cells in uncovering the role of transport across the plasma membrane in cellular inositol homeostasis.
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Affiliation(s)
- B R Fruen
- Department of Genetics, University of Minnesota, Minneapolis 55455
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175
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Mayr GW, Thieleczek R. Masses of inositol phosphates in resting and tetanically stimulated vertebrate skeletal muscles. Biochem J 1991; 280 ( Pt 3):631-40. [PMID: 1764026 PMCID: PMC1130501 DOI: 10.1042/bj2800631] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The masses of inositol phosphates have been determined in isolated skeletal muscles from Xenopus laevis (sartorius, tibialis anterior and iliofibularis) and rat (gastrocnemius and soleus) which were quick-frozen in the resting state and at different stages of an isometric (Xenopus) or isotonic (rat) tetanus. The isomeric spectrum of inositol phosphates detected was similar to that in other tissues and cell types. The total sarcoplasmic concentrations of the isomers Ins-(1,4,5,6)P4/Ins(3,4,5,6)P4 (0.2-0.9 microM), Ins(1,3,4,6)P4 (not detectable), Ins(1,3,4,5,6)P5 (about 1 microM) and InsP6 (3.2-4.6 microM) were lower than in other cell types. Variations in these concentrations were due to the muscle type rather than to the donor species. The putative second messenger Ins(1,4,5)P3, as well as its dephosphorylation product Ins(1,4)P2, were present at surprisingly high total myoplasmic resting concentrations, ranging from 1.2 to 2.5 microM and 3.5 to 6.9 microM respectively. Upon tetanic stimulation these two inositol phosphates in particular exhibited significantly increased total sarcoplasmic concentrations, up to 4.2 microM and 11.3 microM respectively, with a time scale of seconds. From the initial rate of increase in the total sarcoplasmic concentrations of Ins(1,4,5)P3 and its rapidly formed metabolic products, a minimal phosphoinositidase C (PIC) activity in tetanically activated Xenopus skeletal muscle of about 1.7-2.6 microM/s can be estimated. This PIC activity observed in vivo seems to be far too low to account for a functional role for Ins(1,4,5)P3 as a chemical transmitter in the fast excitation-contraction coupling (ECC) process in skeletal muscle. The presence of Ins(1,3,4,5)P4 in all muscle types is indicative of a Ca(2+)-activated Ins(1,4,5)P3 3-kinase activity. The rapid transient increases in Ins(1,3,4)P3 and Ins(1,3)P2 in isometrically contracting Xenopus muscles suggest that corresponding Ins(1,3,4,5)P4 phosphatases are operating in skeletal muscle as well. In all muscles investigated except rat soleus, the fructose 1,6-bisphosphate [Fru(1,6)P2] concentration increased substantially during a tetanus, up to about 2 mM. This increase is correlated with a simultaneous decrease in phosphocreatine, whereas the energy charge of the muscles was essentially unaffected by the applied tetani. The time course of the rise in Fru(1,6)P2 was used to model changes in the free concentrations of high-affinity aldolase-binding inositol phosphates during the course of a tetanus. These calculations demonstrate that the free concentration of Ins(1,4,5)P3 and other aldolase-bound inositol phosphates can increase much faster and to a larger extent than the corresponding total concentrations as a result of their competitive displacement from aldolase-binding sites by the rapidly rising concentration of Fru(1,6)P2.
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Affiliation(s)
- G W Mayr
- Abteilung für Biochemie Supramolekularer Systeme, Ruhr-Universität, Bochum, Federal Republic of Germany
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176
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Hervagault JF, Ortoleva PJ, Ross J. A plausible model for reversal of neoplastic transformations in plants based on multiple steady states. Proc Natl Acad Sci U S A 1991; 88:10797-800. [PMID: 1961748 PMCID: PMC53018 DOI: 10.1073/pnas.88.23.10797] [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: 12/29/2022] Open
Abstract
We offer a plausible interpretation of some experiments on the reversal of neoplastic transformations in plants. We suggest that normal cells and tumorous cells represent multiple stable-steady states corresponding to a reaction feedback mechanism. The (autocatalytic) feedback loop is constructed from observations on the role played by myo-inositol: it increases the permeability of ions through the membrane and the biosynthetic pathway to myo-inositol is activated by ions. Provided that the permeabilities of nutrients (sugars and salts) are a product-enhanced function of myo-inositol, then we have a (oversimplified) model that can exhibit multiple stationary stable states, one or two depending on the exogenous nutrients and myo-inositol concentrations, and reversible and irreversible transitions from one of these states to the other are possible. From this model, straightforward simple experiments are suggested. We also propose that recent models dealing with the intracellular calcium regulation by hormones, where one key step requires the hydrolysis of inositol phospholipids, take into account free myo-inositol and endogenous hormone concentrations (e.g., auxins).
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Affiliation(s)
- J F Hervagault
- Unité de Recherche Associée 1442, Centre National de la Recherche Scientifique, Université de Compiègne, France
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177
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Giembycz MA, Raeburn D. Putative substrates for cyclic nucleotide-dependent protein kinases and the control of airway smooth muscle tone. JOURNAL OF AUTONOMIC PHARMACOLOGY 1991; 11:365-98. [PMID: 1662219 DOI: 10.1111/j.1474-8673.1991.tb00260.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- M A Giembycz
- Department of Thoracic Medicine, National Heart and Lung Institute, Royal Brompton and National Heart and Lung Hospital, London, UK
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178
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Salamończyk GM, Pietrusiewicz K. Expedient synthesis of D - myo - inositol 1,4,5 - trisphosphate and D - myo - inositol 1,4 - bisphosphate. Tetrahedron Lett 1991. [DOI: 10.1016/0040-4039(91)80780-a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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179
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Peter Downes C. Not all mung beans and magic Methods in inositide research. Trends Cell Biol 1991. [DOI: 10.1016/0962-8924(91)90039-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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180
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Leitz T, Wirth A. Vanadate, known to interfere with signal transduction, induces metamorphosis in Hydractinia (Coelenterata; Hydrozoa) and causes profound alterations of the larval and postmetamorphic body pattern. Differentiation 1991. [DOI: 10.1111/j.1432-0436.1991.tb00229.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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181
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Wang P, Anthes J, Siegel M, Egan R, Billah M. Existence of cytosolic phospholipase D. Identification and comparison with membrane-bound enzyme. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98557-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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182
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Scalabrino G, Lorenzini EC. Polyamines and mammalian hormones. Part II: Paracrine signals and intracellular regulators. Mol Cell Endocrinol 1991; 77:37-56. [PMID: 1667762 DOI: 10.1016/0303-7207(91)90057-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- G Scalabrino
- Institute of General Pathology, University of Milan, Italy
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183
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184
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Ferguson JE, Hanley MR. The role of phospholipases and phospholipid-derived signals in cell activation. Curr Opin Cell Biol 1991; 3:206-12. [PMID: 1652988 DOI: 10.1016/0955-0674(91)90140-t] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The complexity of receptor-regulated breakdown and modification of phospholipids continues to grow. New developments extend our concepts of signalling enzymes and possible messengers.
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Affiliation(s)
- J E Ferguson
- Department of Biological Chemistry, School of Medicine, University of California, Davis 95616
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185
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186
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187
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Baquet A, Meijer AJ, Hue L. Hepatocyte swelling increases inositol 1,4,5-trisphosphate, calcium and cyclic AMP concentration but antagonizes phosphorylase activation by Ca2(+)-dependent hormones. FEBS Lett 1991; 278:103-6. [PMID: 1847108 DOI: 10.1016/0014-5793(91)80094-j] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Swelling of hepatocytes increases the concentration of inositol 1,4,5-trisphosphate, Ca2+ and cAMP, without activating glycogen phosphorylase. In these hepatocytes, the activation of phosphorylase by suboptimal concentrations of vasopressin or angiotensin II was partly antagonized.
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Affiliation(s)
- A Baquet
- Hormone and Metabolic Research Unit, University of Louvain Medical School, Brussels, Belgium
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188
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Nahorski SR, John Challiss R. Modulation of receptor-mediated inositol phospholipid breakdown in the brain. Neurochem Int 1991. [DOI: 10.1016/0197-0186(91)90002-u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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189
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Vance DE. Chapter 7 Phospholipid metabolism and cell signalling in eucaryotes. NEW COMPREHENSIVE BIOCHEMISTRY 1991. [DOI: 10.1016/s0167-7306(08)60335-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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190
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Dreef C, Tuinman R, Lefeber A, Elie C, van der Marel G, van Boom J. Synthesis of racemic 3-methylphosphonate analogues of myo-inositol 3,4-bis- and 1,3,4-trisphosphate. Tetrahedron 1991. [DOI: 10.1016/s0040-4020(01)86476-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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191
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Abstract
Interest in phosphoinositide 3-kinase (PI 3-kinase) has been fuelled by its identification as a major phosphotyrosyl protein detected in cells following growth factor stimulation and oncogenic transformation. It is found complexed with activated growth factor receptors and non-receptor tyrosine kinases, thus suggesting that it participates in the signal transduction pathways initiated by the activation of tyrosine kinases. PI 3-kinase phosphorylates the 3-position in the inositol ring of the well known inositol phospholipids in vitro giving phosphatidylinositol 3-phosphate, phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate [PtdIns3P, PtdIns(3,4)P2 and PtdIns(3,4,5)P3], respectively. The cellular levels of PtdIns(3,4)P2 and PtdIns(3,4,5)P3 rapidly increase in circumstances where PI 3-kinase becomes complexed with tyrosine kinases. Accumulation of the same lipids also occurs in platelets and neutrophils following stimulation of G-protein linked alpha-thrombin and chemotactic peptide receptors, respectively, leading to speculation that one or both of these lipids is a new second messenger whose function is not yet known. This review brings together recent information on the isolation, characterization and regulation of PI 3-kinase, the cellular occurrence of 3-phosphorylated inositol phospholipids and possible functions of the PI 3-kinase pathway in cell signalling.
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Affiliation(s)
- C P Downes
- Department Biochemistry, University of Dundee, U.K
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