1
|
Abel A, Wittau N, Wieland T, Schultz G, Kalkbrenner F. Cell cycle-dependent coupling of the vasopressin V1a receptor to different G proteins. J Biol Chem 2000; 275:32543-51. [PMID: 10931825 DOI: 10.1074/jbc.m002171200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Arginine vasopressin (AVP) regulates biological processes by binding to G protein-coupled receptors. In Swiss 3T3 fibroblasts, expressing the V(1a) subtype of vasopressin receptors, AVP mobilizes calcium from intracellular stores. In proliferating cells, the AVP-induced increase in intracellular calcium concentration ([Ca(2+)](i)) was mediated by G proteins of the G(q) family, which are insensitive to pertussis toxin (PTX) pretreatment of the cells. In quiescent cells, the AVP-induced increase in [Ca(2+)](i) was partially PTX-sensitive, suggesting an involvement of G(i) proteins. We confirmed this by photoaffinity labeling of G proteins in Swiss 3T3 cell membranes activated by AVP. In Swiss 3T3 cells arrested in the G(0)/G(1) phase of the cell cycle, the AVP-induced increase in [Ca(2+)](i) was also partially PTX-sensitive but was PTX-insensitive in cells arrested in other phases of the cell cycles. The blocking effect of PTX pretreatment in G(0)/G(1) cells was mimicked by microinjection of antisense oligonucleotides suppressing the expression of the Galpha(i3) subunits. These results were confirmed by microinjection of antibodies directed against the C terminus of G protein alpha-subunits. The data presented indicate that in Swiss 3T3 fibroblasts synchronized in the G(0)/G(1) phase of the cell cycle the V(1a) receptor couples to G(q/11) and G(i3) to activate the phospholipase C-beta, leading to release of intracellular calcium.
Collapse
Affiliation(s)
- A Abel
- Institut für Pharmakologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Thielallee 69-73, D-14195 Berlin, Germany
| | | | | | | | | |
Collapse
|
2
|
Jimenez de Asua L, Goin M, Ortiz M, Gomez de Alzaga MB. A mitogenic and hormonal signalling network regulate mammalian cell division commitment time. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 400A:449-54. [PMID: 9547589 DOI: 10.1007/978-1-4615-5325-0_60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A basic property of mammalian cells is to retain the mitogenically induced "commitment" to undergo DNA replication even in the absence of stimuli. Recent findings on PGF2 alpha and hormone-induced Swiss 3T3 cell multiplication, reveal that this crucial cell cycle event can be regulated by several signalling mechanisms.
Collapse
Affiliation(s)
- L Jimenez de Asua
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Buenos Aires, Argentina
| | | | | | | |
Collapse
|
3
|
Jimenez de Asua L, Goin M. Prostaglandin F2 alpha (PGF2 alpha) triggers protein kinase C (PKC) and tyrosine kinase activity in cultured mammalian cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 400A:531-8. [PMID: 9547601 DOI: 10.1007/978-1-4615-5325-0_72] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Prostaglandin F2 alpha (PGF2 alpha) added to confluent resting Swiss 3T3 cells triggers tyrosine kinase (PTK) activation characterized by the phosphorylation of a set of 75, 86, 110 and 140 kD proteins. PGF2 alpha induces this event independently of PKC activation. However, both PKC and PTK activities appear to act concertedly to cause mitogenesis. Here we discuss their relevance in the control of mammalian cell division.
Collapse
Affiliation(s)
- L Jimenez de Asua
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, (INGEBI), Buenos Aires, Argentina
| | | |
Collapse
|
4
|
Kozawa O, Suzuki A, Uematsu T. Basic fibroblast growth factor induces interleukin-6 synthesis in osteoblasts: autoregulation by protein kinase C. Cell Signal 1997; 9:463-8. [PMID: 9376229 DOI: 10.1016/s0898-6568(97)00043-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We previously reported that basic fibroblast growth factor (bFGF) stimulates both phospholipases C and D via independent pathways in osteoblastlike MC3T3-E1 cells. In this study, we investigated the effect of bFGF on interleukin-6 (IL-6) synthesis in these cells. bFGF stimulated the IL-6 synthesis dose-dependently in the range between 1 and 30 ng/ml. The depletion of extracellular Ca2+ by EGTA suppressed the bFGF-induced IL-6 synthesis. TMB-8, an inhibitor of intracellular Ca2+ mobilization, also inhibited the IL-6 synthesis by bFGF. bFGF stimulated the Ca2+ influx from extracellular space. Genistein, a tyrosine kinase inhibitor, suppressed the bFGF-induced Ca2+ influx. Staurosporine, an inhibitor for protein kinases, enhanced the bFGF-induced IL-6 synthesis. Calphostin C, a highly potent and specific inhibitor for protein kinase C (PKC), also enhanced the IL-6 synthesis by bFGF. The bFGF-induced IL-6 synthesis was amplified in PKC down-regulated cells. U-73122, a phospholipase C inhibitor, enhanced the bFGF-induced IL-6 synthesis. Propranolol, a phosphatidic acid phosphohydrolase inhibitor, also enhanced the IL-6 synthesis by bFGF. These results strongly suggest that bFGF stimulates IL-6 synthesis, which depends on intracellular Ca2+ mobilization in osteoblastlike cells, and that the IL-6 synthesis by bFGF is autoregulated due to PKC activation.
Collapse
Affiliation(s)
- O Kozawa
- Department of Pharmacology, Gifu University School of Medicine, Japan
| | | | | |
Collapse
|
5
|
Hellmich MR, Battey JF, Northup JK. Selective reconstitution of gastrin-releasing peptide receptor with G alpha q. Proc Natl Acad Sci U S A 1997; 94:751-6. [PMID: 9012857 PMCID: PMC19586 DOI: 10.1073/pnas.94.2.751] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Identification of the molecular mechanisms that determine specificity of coupling interactions between gastrin-releasing peptide receptors (GRPrs) and their cognate heterotrimeric GTP-binding proteins is a fundamental step in understanding the signal transduction cascade initiated by receptor-ligand interaction. To explore these mechanisms in greater detail, we have developed an in situ reconstitution assay in chaotrope-extracted membranes from mouse fibroblasts expressing the GRPr, and we have used it to measure GRPr-catalyzed binding of GTP gamma S to purified G protein alpha subunits. Binding studies with 125I-labeled [D-Tyr6]bombesin(6-13) methyl ester (125I-Tyr-ME), a GRPr specific antagonist, show a single binding site with a Kd = 1.4 nM +/- 0.4 (mean +/- SD, n = 3) and capacity of 15-22 pmol of receptor per mg of protein in the extracted membrane preparations, representing a 2- to 3-fold enrichment of binding sites compared with the membranes before extraction. Quantitative ligand displacement analysis using various unlabeled GRPr agonists shows a rank order of potency characteristic of the GRPr: bombesin > or = GRP > > neuromedin B. Reconstitution of urea extracted membranes with a purified G alpha q showed that receptor-catalyzed binding of GTP gamma S was dependent on agonist (GRP) and G beta gamma subunits. The EC50 for GRP was 3.5 nM, which correlates well with the reported Kd of 3.1 nM for GRP binding to GRPr expressed in mouse fibroblasts [Benya, R. V., et al. (1994) Mol. Pharmacol. 46, 235-245]. The apparent Kd for bovine brain G beta gamma in this assay was 60 nM, and the Km for squid retinal G alpha q was 90 nM. The GRPr-catalyzed binding of GTP gamma S is selective for G alpha q, since we did not detect receptor-catalyzed exchange using either G alpha i/o or G alpha t. These data demonstrate that GRPr can functionally couple to G alpha q but not to the pertussis toxin-sensitive G alpha i/o or retinal specific G alpha t. This in situ receptor reconstitution method will allow molecular characterization of G protein coupling to other heptahelical receptors.
Collapse
Affiliation(s)
- M R Hellmich
- Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, Rockville, MD 20850, USA
| | | | | |
Collapse
|
6
|
Suzuki A, Shinoda J, Kanda S, Oiso Y, Kozawa O. Basic fibroblast growth factor stimulates phosphatidylcholine-hydrolyzing phospholipase D in osteoblast-like cells. J Cell Biochem 1996; 63:491-9. [PMID: 8978464 DOI: 10.1002/(sici)1097-4644(19961215)63:4<491::aid-jcb10>3.0.co;2-h] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We examined the effect of basic fibroblast growth factor (bFGF) on the activation of phosphatidylcholine-hydrolyzing phospholipase D in osteoblast-like MC3T3-E1 cells. bFGF stimulated both the formations of choline (EC50 was 30 ng/ml) and inositol phosphates (EC50 was 10 ng/ml). Calphostin C, an inhibitor of protein kinase C (PKC), had little effect on the bFGF-induced formation of choline. bFGF stimulated the formation of choline also in PKC down regulated cells. Genistein and methyl 2,5-dihydroxycinnamate, inhibitors of protein tyrosine kinases, significantly suppressed the bFGF-induced formation of choline. Sodium orthovanadate, an inhibitor of protein tyrosine phosphatases, enhanced the bFGF-induced formation of choline. In vitro kinase assay for FGF receptors revealed that FGF receptor 1 and 2 were autophosphorylated after FGF stimulation. bFGF dose-dependently stimulated DNA synthesis of these cells. These results strongly suggest that bFGF activates phosphatidylcholine-hydrolyzing phospholipase D through the activation of tyrosine kinase, but independently of PKC activated by phosphoinositide hydrolysis in osteoblast-like cells.
Collapse
Affiliation(s)
- A Suzuki
- First Department of Internal Medicine, Nagoya University, School of Medicine, Japan
| | | | | | | | | |
Collapse
|
7
|
Hall H, Williams EJ, Moore SE, Walsh FS, Prochiantz A, Doherty P. Inhibition of FGF-stimulated phosphatidylinositol hydrolysis and neurite outgrowth by a cell-membrane permeable phosphopeptide. Curr Biol 1996; 6:580-7. [PMID: 8805278 DOI: 10.1016/s0960-9822(02)00544-4] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Activated receptor tyrosine kinases bind downstream effector molecules with high affinity. Provided that they can be introduced into cells, peptides corresponding to these high-affinity sites should be able to compete for the interaction and thereby inhibit specific signal transduction cascades. The high-affinity binding site for phospholipase C gamma (PLCgamma) on the activated fibroblast growth factor receptor (FGFR) is centred around the tyrosine at position 766 (766Tyr), and peptides corresponding to this site inhibit PLCgamma binding to the receptor in vitro. A 16 amino-acid peptide from the third helix of the Antennapedia homeodomain protein has recently been shown to be able to act as an internalization vector that can deliver other peptides into cells. Here, we have designed a peptide that contains both the internalization sequence and the FGFR high-affinity binding site for PLCgamma, and tested it in cultures of cerebellar neurons for its ability to inhibit the activation of PLCgamma by basic FGF. RESULTS The peptide containing the FGFR high-affinity binding site for PLCgamma inhibited phospholipid hydrolysis stimulated by basic FGF with a maximal effect at 1 microg ml-1. Phosphorylation of 766Tyr was required for this effect. The phosphorylated peptide had no effect on phospholipid hydrolysis stimulated by platelet-derived growth factor, neurotrophin-3 and bradykinin. The phosphorylated peptide also inhibited neurite outgrowth stimulated by FGF, but had no effect on neurite outgrowth stimulated by agents that activate the FGFR signal transduction cascade downstream from the activation of PLCgamma. CONCLUSIONS Cell-permeable peptides can be designed that inhibit the function of receptor tyrosine kinases. In this context we have developed a peptide that prevents the FGFR from activating PLCgamma, and have used this peptide to obtain the first direct evidence that activation of PLCgamma is required for the neurite outgrowth response stimulated by basic FGF.
Collapse
Affiliation(s)
- H Hall
- Department of Experimental Pathology, UMDS, Guy's Hospital, London Bridge, London SE1 9RT, UK
| | | | | | | | | | | |
Collapse
|
8
|
Solan JL, Deftos LJ, Goding JW, Terkeltaub RA. Expression of the nucleoside triphosphate pyrophosphohydrolase PC-1 is induced by basic fibroblast growth factor (bFGF) and modulated by activation of the protein kinase A and C pathways in osteoblast-like osteosarcoma cells. J Bone Miner Res 1996; 11:183-92. [PMID: 8822342 DOI: 10.1002/jbmr.5650110207] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The closely related cytokines bFGF and aFGF regulate the function of bone cells and mineralization. Osteoblasts express PPi-generating nucleoside triphosphate pyrophosphohydrolase (NTPPPH)/nucleotide phosphodiesterase I activity. bFGF and aFGF (10 ng/ml) up-regulated NTPPPH in human SaOS-2 and U2OS osteosarcoma cells, which express osteoblast-like features in culture. The induction was selective as alkaline phosphatase activity was down-regulated and specific as insulin-like growth factor-1 (IGF-1) and interleukin-1 beta (IL-1 beta) were not active. Furthermore, IL-1 beta but not IGF-1 inhibited bFGF-induced up-regulation of NTPPPH. The induced NTPPPH remained predominantly associated with cells. bFGF can induce signaling through pathways including protein kinase A (PKA) and protein kinase C (PKC)-mediated transduction. An activator of the PKA pathway (8-bromo cyclic adenosine monophosphate [cAMP]) induced NTPPPH. Furthermore, pretreatment with the PKC activator phorbol myristate acetate (PMA) (80 nM) markedly increased subsequent NTPPPH induction by both bFGF and cAMP. The PMA effect was associated with morphologic changes characterized by long, thin intercellular extensions. PKC desensitization also potentially contributed to this effect because the PKC inhibitors staurosporine and H-7 enhanced bFGF-induced and cAMP-induced NTPPPH expression in the absence of morphologic changes. We observed that bFGF induced expression of PC-1, a member of the NTPPPH gene family. The majority of NTPPPH activity was depleted by immunoadsorption using a monoclonal antibody to native human PC-1. bFGF- and aFGF-induced production of PC-1/NTPPPH in osteoblastoid cells may contribute to the effects of FGFs on bone metabolism.
Collapse
Affiliation(s)
- J L Solan
- Department of Medicine, University of California--San Diego, USA
| | | | | | | |
Collapse
|
9
|
Affiliation(s)
- G S Kroog
- Laboratory of Neurochemistry, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland, USA
| | | | | |
Collapse
|
10
|
Yang L, Rhee S, Williamson J. Epidermal growth factor-induced activation and translocation of phospholipase C-gamma 1 to the cytoskeleton in rat hepatocytes. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37261-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
11
|
Dobrzanski D, Sharoni Y, Wada E, Battey J, Sausville E. Neuromedin-B receptor transfected BALB/3T3 cells: signal transduction and effects of ectopic receptor expression on cell growth. REGULATORY PEPTIDES 1993; 45:341-52. [PMID: 8394594 DOI: 10.1016/0167-0115(93)90360-k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bombesin-like peptides including neuromedin B have been proposed as autocrine or paracrine growth factors for carcinomas. To examine signal transduction and regulation of cell growth by NMB, transfectants were created with the rat NMB receptor (NMB-R) gene in BALB/3T3 cells which do not express an endogenous bombesin peptide receptor. The resultant cell line, NMB-8, expresses 800,000 NMB binding sites/cell. Addition of NMB has a biphasic effect on [3H]thymidine ([3H]dT) incorporation in confluent and quiescent cells: up to 10 nM of NMB causes a 1.5-3-fold stimulation of [3H]dT incorporation, but at greater than 10 nM there is inhibition of [3H]dT incorporation, and at 100 nM of NMB there is inhibition of cell growth. NMB causes protracted increases in intracellular Ca2+, and pertussis toxin (PT)-insensitive phosphatidylinositol (PI) turnover. NMB-mediated increase in membrane phospholipase-C activity is stimulated by guanosine 5'-O-(3-thiotriphosphate). Arachidonate release is also activated by NMB in a PT-insensitive manner. Brief exposure to 12-tetradecanoylphorbol 13-acetate inhibits NMB-mediated PI turnover but not arachidonate release. Thus, in NMB-8 cells, distinct mechanisms govern NMB-mediated phospholipase-C activation and arachidonate release. Also, neuromedin-B is potentially a bifunctional regulator of cell growth.
Collapse
Affiliation(s)
- D Dobrzanski
- Laboratory of Biological Chemistry, National Cancer Institute, Bethesda, MD
| | | | | | | | | |
Collapse
|
12
|
Buhl AM, Eisfelder BJ, Worthen GS, Johnson GL, Russell M. Selective coupling of the human anaphylatoxin C5a receptor and alpha 16 in human kidney 293 cells. FEBS Lett 1993; 323:132-4. [PMID: 8388335 DOI: 10.1016/0014-5793(93)81464-b] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The peptide C5a which is generated during the complement cascade is an important chemotactic factor involved in the inflammatory response. The C5a receptor (C5aR) primary sequence suggests that it has a serpentine structure of seven transmembrane domains which is typical of classical G-protein-coupled receptors. To investigate the signal transduction mechanism of C5a we transiently expressed the C5aR in combination with different G-protein alpha subunits in human kidney 293 cells and measured the PLC activity induced upon C5a stimulation. Cotransfection of C5aR and alpha 16 stimulated PLC while cotransfection of C5aR with either alpha q or alpha i2 did not.
Collapse
Affiliation(s)
- A M Buhl
- Department of Biostructural Chemistry, Aarhus University, Denmark
| | | | | | | | | |
Collapse
|
13
|
Yang L, Camoratto A, Baffy G, Raj S, Manning D, Williamson J. Epidermal growth factor-mediated signaling of G(i)-protein to activation of phospholipases in rat-cultured hepatocytes. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53756-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
14
|
Goin M, Pignataro O, Jimenez de Asua L. Early cell cycle diacylglycerol (DAG) content and protein kinase C (PKC) activity enhancement potentiates prostaglandin F2 alpha (PGF2 alpha) induced mitogenesis in Swiss 3T3 cells. FEBS Lett 1993; 316:68-72. [PMID: 8380777 DOI: 10.1016/0014-5793(93)81738-l] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
R59022, a diacylglycerol kinase inhibitor, enhances the prostaglandin F2 alpha (PGF2 alpha)-induced diacylglycerol (DAG) synthesis in Swiss 3T3 cells. It also potentiates the PGF2 alpha-mediated protein kinase C (PKC)-dependent 80 kDa protein (80K) phosphorylation and initiation of DNA replication. R59022 enhances the PGF2 alpha mitogenic response by increasing the rate of entry into the S phase. Insulin does not cause 80K phosphorylation, and does not enhance its induction but it potentiates the PGF2 alpha mitogenic response. These results suggest that mitogenically triggered fluctuations in DAG content and PKC activity play a pivotal role in controlling the PGF2 alpha-induced DNA synthesis while insulin acts via a different mechanism.
Collapse
Affiliation(s)
- M Goin
- Instituto de Investigaciones en Ingenieria Genetica y Biologia Molecular (INGEBI), Buenos Aires, Argentina
| | | | | |
Collapse
|
15
|
Spindel ER, Giladi E, Segerson TP, Nagalla S. Bombesin-like peptides: of ligands and receptors. RECENT PROGRESS IN HORMONE RESEARCH 1993; 48:365-91. [PMID: 8382830 DOI: 10.1016/b978-0-12-571148-7.50017-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- E R Spindel
- Division of Neuroscience, Oregon Regional Primate Research Center, Beaverton 97006
| | | | | | | |
Collapse
|
16
|
Nishimura J, Kobayashi S, Shikasho T, Kanaide H. Platelet derived growth factor induces c-fos and c-myc mRNA in rat aortic smooth muscle cells in primary culture without elevation of intracellular Ca2+ concentration. Biochem Biophys Res Commun 1992; 188:1198-204. [PMID: 1445353 DOI: 10.1016/0006-291x(92)91358-w] [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: 12/27/2022]
Abstract
Platelet derived growth factor (PDGF) has been shown to induce c-fos and c-myc proto-oncogenes. In the present study, we investigated the effects of genistein, a tyrosine kinase inhibitor, and NiCl2, a Ca2+ influx blocker, on PDGF-induced Ca2+ transient and on expression of c-fos and c-myc mRNA. In the presence of extracellular Ca2+, PDGF induced elevation of intracellular Ca2+ concentration ([Ca2+]i) and increases in c-fos and c-myc mRNA, as detected by reverse transcription polymerase chain reaction (RT-PCR) and Northern hybridization. PDGF-induced [Ca2+]i elevation was composed of an initial transient increase (first component) followed by steady state elevation (second component). Genistein (10 microM) blocked the 1st, but not the 2nd, component of [Ca2+]i elevation induced by PDGF. NiCl2 (1 mM) and removal of extracellular Ca2+ inhibited the 2nd, but not the 1st, component. In the presence of 10 microM genistein and 1 mM NiCl2, PDGF induced c-fos and c-myc mRNA, although the [Ca2+]i elevation could be completely blocked by these two agents. These results indicate that elevation of [Ca2+]i is not a prerequisite condition for PDGF to induce c-fos and/or c-myc mRNA in rat aortic smooth muscle cells in primary culture.
Collapse
Affiliation(s)
- J Nishimura
- Division of Molecular Cardiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
| | | | | | | |
Collapse
|
17
|
Cockcroft S, Thomas GM. Inositol-lipid-specific phospholipase C isoenzymes and their differential regulation by receptors. Biochem J 1992; 288 ( Pt 1):1-14. [PMID: 1332691 PMCID: PMC1132071 DOI: 10.1042/bj2880001] [Citation(s) in RCA: 290] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S Cockcroft
- Department of Physiology, University College London, U.K
| | | |
Collapse
|
18
|
Seseke FG, Gardemann A, Jungermann K. Signal propagation via gap junctions, a key step in the regulation of liver metabolism by the sympathetic hepatic nerves. FEBS Lett 1992; 301:265-70. [PMID: 1577164 DOI: 10.1016/0014-5793(92)80254-e] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cell-to-cell communication via gap junctions has been proposed to be involved in the metabolic actions of sympathetic liver nerves in the rat. The effects of hepatic nerve stimulation and noradrenaline-, PGF2 alpha- and glucagon infusion on glucose metabolism and perfusion flow were studied in perfused rat liver in the absence and presence of the gap junctional inhibitors, heptanol, carbenoxolone and (4 beta)phorbol 12-myristate 13-acetate (4 beta PMA). (i) Stimulation of the hepatic nerve plexus increased glucose output, decreased flow and caused an overflow of noradrenaline into the hepatic vein. (ii) Heptanol completely inhibited not only the nerve stimulation-dependent metabolic and hemodynamic alterations but also the noradrenaline overflow. Thus the heptanol-dependent inhibitions were caused primarily by a strong impairment of transmitter release. (iii) Carbenoxolone inhibited the effects of neurostimulation on glucose metabolism partially by about 50%, whereas it left perfusion flow and noradrenaline overflow essentially unaltered. (iv) 4 beta PMA reduced the nerve stimulation-dependent enhancement of glucose release by about 80% but the noradrenaline-dependent increase in glucose output only by about 30%; the increase in glucose release by PGF2 alpha and by glucagon remained essentially unaltered. 4 beta PMA reduced the nerve stimulation-dependent decrease in portal flow by about 35% but did not affect the noradrenaline-and PGF2 alpha-elicited alterations, nor did it alter noradrenaline overflow. The results allow the conclusion that gap junctional communication plays a major role in the regulation of hepatic carbohydrate metabolism by sympathetic liver nerves, but not by circulating noradrenaline, PGF2 alpha or glucagon.
Collapse
Affiliation(s)
- F G Seseke
- Institut für Biochemie, Universität Göttingen, Germany
| | | | | |
Collapse
|
19
|
Goin M, Jimenez de Asua L. Stimulation of protein kinase C (PKC) activity in resting Swiss 3T3 cells by prostaglandin F2 alpha. FEBS Lett 1992; 297:175-8. [PMID: 1551425 DOI: 10.1016/0014-5793(92)80354-j] [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: 12/27/2022]
Abstract
Prostaglandin F2 alpha (PGF2 alpha), a mitogen for resting Swiss 3T3 cells, rapidly stimulates phosphorylation of an 80 kDa protein (80 K). 1-Oleoyl-2-acetylglycerol (OAG) and 12-O-tetradecanoyl phorbol-13-acetate (TPA) both protein kinase C (PKC) activators, also elicit 80 K phosphorylation. In contrast PGE1, PGE2 or PGF2 beta, which are non-mitogenic in these cells, had little or no action on this event. However PGE1 and PGE2 potentiate the PGF2 alpha proliferative effect but do not enhance its action on 80 K phosphorylation. These results suggest that PGF2 alpha mitogenic induction involves PKC signalling pathway activation while its enhancement by PGE1 or PGE2 occurs through a different mechanism(s).
Collapse
Affiliation(s)
- M Goin
- Instituto de Investigaciones en Ingenieria Genética y Biologia Molecular (INGEBI), Buenos Aires, Argentina
| | | |
Collapse
|
20
|
Cook SJ, Wakelam MJ. Phospholipases C and D in mitogenic signal transduction. Rev Physiol Biochem Pharmacol 1992; 119:13-45. [PMID: 1604152 DOI: 10.1007/3540551921_2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- S J Cook
- Department of Molecular Biology, Cetus Corporation, Emeryville, CA 94608
| | | |
Collapse
|
21
|
Raspé E, Reuse S, Roger PP, Dumont JE. Lack of correlation between the activation of the Ca(2+)-phosphatidylinositol cascade and the regulation of DNA synthesis in the dog thymocyte. Exp Cell Res 1992; 198:17-26. [PMID: 1727052 DOI: 10.1016/0014-4827(92)90143-v] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Changes in the [Ca2+]i and/or activation of phospholipase C are thought to participate in the control by several growth factors of the mammalian cell proliferation. It has even been claimed that activation of the Ca(2+)-phosphatidylinositol cascade is sufficient to elicit cell proliferation [Jackson et al. (1988) Nature 335, 437-440; Julius et al. (1989) Science 244, 1057-1062]. In this work, we have evaluated the control of DNA synthesis by this cascade in a differentiated epithelial cell model: the dog thyrocyte in primary culture. We first observed that potent activators of the dog thyrocyte (2+)-phosphatidylinositol cascade such as carbachol or bradykinin failed to promote the onset of DNA synthesis in these cells. Moreover, carbachol inhibited the mitogenic effect of thyroid stimulating hormone (TSH) and of epidermal growth factor (EGF). The mitogenic effect of EGF was also reduced by bradykinin. Nevertheless, carbachol enhanced the expression of the protooncogenes c-fos and c-myc mRNAs. The time course of this enhancement was identical to the time course for the induction of c-fos and c-myc mRNAs by phorbol esters or EGF. On the other hand, in most experiments, TSH and EGF were able to trigger the onset of dog thyrocyte DNA synthesis without affecting their intracellular free Ca2+ concentration [Ca2+]i, 45Ca2+ efflux, or inositol phosphate generation. In several experiments, TSH increased the dog thyrocyte 45Ca2+ release and promoted a rise in the [Ca2+]i or the inositol phosphate accumulation but these effects were weak. In contrast to the effect of carbachol, the TSH effects on the [Ca2+]i and the 45Ca2+ efflux appeared slowly, were sustained, and were extremely sensitive to extracellular Ca2+ depletion. They were observed at hormone concentrations higher than the concentration achieving maximal stimulation of DNA synthesis. Similarly, in a few experiments, a slight increase in the [Ca2+]i or in the inositol trisphosphate generation were provoked by EGF. However, these modifications were not associated with an increased mitogenic potency of EGF. Finally, in all experiments, fetal calf serum slightly accelerated the dog thyrocyte 45Ca2+ efflux and increased their inositol phosphate generation.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- E Raspé
- IRIBHN, School of Medicine, Free University of Brussels, Belgium
| | | | | | | |
Collapse
|
22
|
Ogino Y, Costa T. The epithelial phenotype of human neuroblastoma cells express bradykinin, endothelin, and angiotensin II receptors that stimulate phosphoinositide hydrolysis. J Neurochem 1992; 58:46-56. [PMID: 1309239 DOI: 10.1111/j.1471-4159.1992.tb09275.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The neuroblastoma line SK-N-SH consists of distinct and interconverting cell types, which include a neuroblast phenotype (SH-SY5Y), an epithelial phenotype (SH-EP), and an intermediate cell type (SH-IN). In SH-SY5Y cells, only muscarinic receptor activation produced stimulation of phosphoinositide turnover, whereas in SH-EP cells, where muscarinic receptors are not present, the peptides bradykinin, endothelin, and angiotensin II stimulated phosphoinositide hydrolysis with EC50 values of 16, 6, and 0.7 nM, respectively, and a rank order of maximal effects of bradykinin greater than endothelin greater than angiotensin II. Fetal calf serum at concentrations between 1 and 10% was also a potent stimulator of phosphoinositide hydrolysis in SH-EP cells but not in SH-SY5Y cells. In the intermediate cell clone, SH-IN, phosphoinositide hydrolysis was stimulated not only by muscarinic receptors, but also by endothelin, bradykinin, and serum, an indication that this cell type harbors all the kinds of receptors that are differentially expressed in the other two cell types. The effects of the three peptides--bradykinin, endothelin, and angiotensin II--on phosphoinositide hydrolysis in SH-EP cells were additive, a result suggesting that the three kinds of receptors may activate distinct transducer proteins and/or phospholipase C subtypes. Pretreatment of intact SH-EP cells with pertussis toxin under conditions sufficient to ADP-ribosylate 90-95% of the endogenous guanine nucleotide regulatory protein substrates did not impair the ability of any of the receptors to stimulate phosphoinositide hydrolysis in any of the cell types. In contrast, short-term exposure to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (1 microM) abolished the stimulation of phosphoinositide hydrolysis mediated by peptide receptors in SH-EP cells and partially inhibited that by muscarinic receptors in SH-SY5Y cells. Prolonged incubation of SH-EP cells with phorbol ester resulted in a recovery of receptor responsiveness, the extent and rate of which were different for each receptor type. In contrast, there was no recovery of responsiveness for muscarinic receptors in SH-SY5Y cells. The pattern of phorbol ester-mediated effects depended on the cell rather than on the receptor type. In fact, muscarinic receptor responsiveness in SH-IN, the intermediate cell type, was desensitized by and recovered from treatment with phorbol esters in a manner more similar to peptide receptors in SH-EP than to muscarinic receptors in SH-SY5Y. These data suggest that the transduction mechanisms by which distinct receptor types are coupled to phosphoinositide hydrolysis in the three cell phenotypes differ in sensitivity to feedback regulation by protein kinase C.
Collapse
Affiliation(s)
- Y Ogino
- Laboratory of Theoretical and Physical Biology, NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | | |
Collapse
|
23
|
Staddon JM, Bouzyk MM, Rozengurt E. A novel approach to detect toxin-catalyzed ADP-ribosylation in intact cells: its use to study the action of Pasteurella multocida toxin. J Cell Biol 1991; 115:949-58. [PMID: 1835459 PMCID: PMC2289951 DOI: 10.1083/jcb.115.4.949] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Certain microbial toxins are ADP-ribosyltransferases, acting on specific substrate proteins. Although these toxins have been of great utility in studies of cellular regulatory processes, a simple procedure to directly study toxin-catalyzed ADP-ribosylation in intact cells has not been described. Our approach was to use [2-3H]adenine to metabolically label the cellular NAD+ pool. Labeled proteins were then denatured with SDS, resolved by PAGE, and detected by flurography. In this manner, we show that pertussis toxin, after a dose-dependent lag period, [3H]-labeled a 40-kD protein intact cells. Furthermore, incubation of the gel with trichloroacetic acid at 95 degrees C before fluorography caused the release of label from bands other than the pertussis toxin substrate, thus, allowing its selective visualization. The modification of the 40-kD protein was ascribed to ADP-ribosylation of a cysteine residue on the basis of inhibition of labeling by nicotinamide and the release of [3H]ADP-ribose from the labeled protein by mercuric acetate. Cholera toxin catalyzed the [3H]-labeling of a 46-kD protein in the [2-3H]adenine-labeled cells. Pretreatment of the cells with pertussis toxin before the labeling of NAD+ with [2-3H]adenine blocked [2-3H]ADP-ribosylation catalyzed by pertussis toxin, but not that by cholera toxin. Thus, labeling with [2-3H]adenine permits the study of toxin-catalyzed ADP-ribosylation in intact cells. Pasteurella multocida toxin has recently been described as a novel and potent mitogen for Swiss 3T3 cell and acts to stimulate the phospholipase C-mediated hydrolysis of polyphosphoinositides. The basis of the action of the toxin is not known. Using the methodology described here, P. multocida toxin was not found to act by ADP-ribosylation.
Collapse
Affiliation(s)
- J M Staddon
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, United Kingdom
| | | | | |
Collapse
|
24
|
Yang L, Baffy G, Rhee S, Manning D, Hansen C, Williamson J. Pertussis toxin-sensitive Gi protein involvement in epidermal growth factor-induced activation of phospholipase C-gamma in rat hepatocytes. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54593-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
25
|
Masuda N, Ui M. Possible involvement of GTP-binding proteins in growth regulation of human epidermoid carcinoma cell line A431. FEBS Lett 1991; 291:9-12. [PMID: 1936256 DOI: 10.1016/0014-5793(91)81091-l] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A431 cells, a human epidermoid carcinoma cell line, express an unusually large number of cell surface receptors for the epidermal growth factor (EGF). The growth rate of A431 cells was estimated by measuring [3H]thymidine incorporation at the logarithmic growth phase. The growth of the cells in protein-free medium was partially inhibited by exposure of the cells to pertussis toxin, islet-activating protein (IAP). The growth in both serum-containing and protein-free medium was inhibited by high concentrations of EGF, and these inhibitions were partially reversed by treatment of the cells with IAP. The effects of IAP were well correlated with the degree of ADP-ribosylation of a membrane 40-kDa protein. Thus, IAP sensitive G-proteins appear to be involved in the signal transduction of both positive and negative regulation of A431 cell growth. The possibility is also discussed that phosphatidylinositol turnover may participate in growth regulation.
Collapse
Affiliation(s)
- N Masuda
- Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan
| | | |
Collapse
|
26
|
Cui Z, Zubiaur M, Bloch D, Michel T, Seidman J, Neer E. Expression of a G protein subunit, alpha i-1, in Balb/c 3T3 cells leads to agonist-specific changes in growth regulation. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54919-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
27
|
Récasens M, Guiramand J, Vignes M. The putative molecular mechanism(s) responsible for the enhanced inositol phosphate synthesis by excitatory amino acids: an overview. Neurochem Res 1991; 16:659-68. [PMID: 1686474 DOI: 10.1007/bf00965552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- M Récasens
- Laboratoire de Neurobiologie de l'Audition, Université Montpellier II, Hôpital St Charles, France
| | | | | |
Collapse
|
28
|
Abstract
Many hormones, growth factors, and neurotransmitters stimulate their target cells by promoting the hydrolysis of plasma-membrane phosphoinositides to form the two second messengers, diacylglycerol and inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. In such cells, ligand-receptor interaction stimulates specific phospholipases that are activated by guanyl nucleotide regulatory G proteins or tyrosine phosphorylation. In many cells, the initial rise in cytoplasmic calcium due to Ins(1,4,5)P3-induced mobilization of calcium from agonist-sensitive stores is followed by a sustained phase of cytoplasmic calcium elevation that maintains the target-cell response, and is dependent on influx of extracellular calcium. Numerous inositol phosphates are formed during metabolism of the calcium-mobilizing messenger, inositol 1,4,5-trisphosphate [Ins(1,4,5)P3], to lower and higher phosphorylated derivatives. The cloning of several phospholipase-C isozymes, as well as the Ins(1,4,5)P3-5 kinase and the Ins(1,4,5)P3 receptor, have clarified several aspects of the diversity and complexity of the phosphoinositide-calcium signaling system. In addition to their well-established roles in hormonal activation of cellular responses such as secretion and contraction, phospholipids and their hydrolysis products have been increasingly implicated in the actions of growth factors and oncogenes on cellular growth and proliferation.
Collapse
Affiliation(s)
- K J Catt
- Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | | | | |
Collapse
|
29
|
Abstract
There is a large body of evidence supporting a role for GTP-binding proteins in signal transduction by growth factors. In certain cells, ligands which activate or inhibit the production of cAMP via heterotrimeric G proteins promote replication of the target cell. These mechanisms play an important role in a limited number of tumours. Ligands which activate PI hydrolysis through heterotrimeric G proteins may also promote growth in certain systems, but the precise role for PI hydrolysis remains to be determined. Receptors with intrinsic tyrosine kinases may also interact with the heterotrimeric G proteins, but it is not known if these interactions represent side reactions, or whether they are central in the responses of certain cell types. Lastly, p21ras and other small molecular weight G proteins appear to be profoundly important in growth control. The tyrosine kinase growth factor receptors may interact indirectly with these GTP binding proteins via GAP proteins. The molecular detail of this process is emerging rapidly and is likely to be worked out in the near future.
Collapse
Affiliation(s)
- H E Ives
- Department of Medicine, University of California, San Francisco 94143
| |
Collapse
|
30
|
Feldman RI, Wu JM, Jenson JC, Mann E. Purification and characterization of the bombesin/gastrin-releasing peptide receptor from Swiss 3T3 cells. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)44911-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
31
|
Hepler JR, Jeffs RA, Huckle WR, Outlaw HE, Rhee SG, Earp HS, Harden TK. Evidence that the epidermal growth factor receptor and non-tyrosine kinase hormone receptors stimulate phosphoinositide hydrolysis by independent pathways. Biochem J 1990; 270:337-44. [PMID: 1698055 PMCID: PMC1131726 DOI: 10.1042/bj2700337] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have shown previously that exposure of a non-transformed continuous line of rat liver epithelial (WB) cells to epidermal growth factor (EGF), adrenaline, angiotensin II or [Arg8]vasopressin results in an accumulation of the inositol phosphates InsP1, InsP2 and InsP3 [Hepler, Earp & Harden (1988) J. Biol. Chem. 263, 7610-7619]. Studies were carried out with WB cells to determine whether the EGF receptor and other, non-tyrosine kinase, hormone receptors stimulate phosphoinositide hydrolysis by common, overlapping or separate pathways. The time courses for accumulation of inositol phosphates in response to angiotensin II and EGF were markedly different. Whereas angiotensin II stimulated a very rapid accumulation of inositol phosphates (maximal by 30 s), increases in the levels of inositol phosphates in response to EGF were measurable only following a 30 s lag period; maximal levels were attained by 7-8 min. Chelation of extracellular Ca2+ with EGTA did not modify this relative difference between angiotensin II and EGF in the time required to attain maximal phospholipase C activation. Under experimental conditions in which agonist-induced desensitization no longer occurred in these cells, the inositol phosphate responses to EGF and angiotensin II were additive, whereas those to angiotensin II and [Arg8]vasopressin were not additive. In crude WB lysates, angiotensin II, [Arg8]vasopressin and adrenaline each stimulated inositol phosphate formation in a guanine-nucleotide-dependent manner. In contrast, EGF failed to stimulate inositol phosphate formation in WB lysates in the presence or absence of guanosine 5'-[gamma-thio]triphosphate (GTP[S]), even though EGF retained the capacity to bind to and stimulate tyrosine phosphorylation of its own receptor. Pertussis toxin, at concentrations that fully ADP-ribosylate and functionally inactivate the inhibitory guanine-nucleotide regulatory protein of adenylate cyclase (Gi), had no effect on the capacity of EGF or hormones to stimulate inositol phosphate accumulation. In intact WB cells, the capacity of EGF, but not angiotensin II, to stimulate inositol phosphate accumulation was correlated with its capacity to stimulate tyrosine phosphorylation of the 148 kDa isoenzyme of phospholipase C. Taken together, these findings suggest that, whereas angiotensin II, [Arg8]vasopressin and alpha 1-adrenergic receptors are linked to activation of one or more phospholipase(s) C by an unidentified G-protein(s), the EGF receptor stimulates phosphoinositide hydrolysis by a different pathway, perhaps as a result of its capacity to stimulate tyrosine phosphorylation of phospholipase C-gamma.
Collapse
Affiliation(s)
- J R Hepler
- Department of Pharmacology, School of Medicine, University of North Carolina, Chapel Hill 27599
| | | | | | | | | | | | | |
Collapse
|
32
|
Plevin R, Palmer S, Gardner SD, Wakelam MJ. Regulation of bombesin-stimulated inositol 1,4,5-trisphosphate generation in Swiss 3T3 fibroblasts by a guanine-nucleotide-binding protein. Biochem J 1990; 268:605-10. [PMID: 2114096 PMCID: PMC1131481 DOI: 10.1042/bj2680605] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The stimulation of inositol phosphate generation by bombesin and GTP analogues was studied in Swiss 3T3 cells permeabilized by electroporation. Bombesin-stimulated inositol phosphate generation is potentiated by guanosine 5'-[gamma-thio]triphosphate (GTP[S]) and inhibited by guanosine 5'-[beta-thio]diphosphate at all peptide concentrations tested, with no change in the EC50 value (concn. giving half-maximal response) for the agonist. Kinetic analysis showed that, although bombesin-stimulated [3H]InsP3 generation in [3H]inositol-labelled cells was rapid (maximal by 5-10 s), the response to GTP[S] alone displayed a distinct lag time of 20-30 s. This lag time was significantly decreased by the addition of bombesin, suggesting that in this system agonist-stimulated GTP/GDP exchange occurs. In addition, bombesin-stimulated generation of Ins(1,4,5)P3 mass at 10 s was enhanced by GTP[S] in the absence of a nucleotide response alone, a result consistent with this proposal. Pretreatment of the cells with phorbol 12-myristate 13-acetate (PMA) resulted in a dose-dependent inhibition of bombesin-, but not GTP[S]-, stimulated inositol phosphate generation. Furthermore, although PMA pretreatment did not affect the lag time for InsP3 formation in response to GTP[S] alone, the degree of synergy between bombesin and the nucleotide was severely decreased at early time points. The results therefore demonstrate that the high-affinity bombesin receptor is coupled via a G-protein to phospholipase C in a manner consistent with a general model for receptor-G-protein interactions and that this coupling is sensitive to phosphorylation by protein kinase C.
Collapse
Affiliation(s)
- R Plevin
- Department of Biochemistry, University of Glasgow, Scotland, U.K
| | | | | | | |
Collapse
|
33
|
Black FM, Wakelam MJ. Activation of inositol phospholipid breakdown by prostaglandin F2 alpha without any stimulation of proliferation in quiescent NIH-3T3 fibroblasts. Biochem J 1990; 266:661-7. [PMID: 2327955 PMCID: PMC1131190 DOI: 10.1042/bj2660661] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stimulation of NIH-3T3 cells with prostaglandin F2 alpha (PGF2 alpha) caused a dose- and time-dependent generation of inositol phosphates. The first detectable changes were in the levels of Ins(1,4,5)P3 and Ins(1,3,4,5)P4. Increases in Ins(1,3,4)P3, InsP2 and InsP were detected later, and only minor changes were observed in putative InsP5 or InsP6. The accumulation of inositol phosphates was synergistically increased by the addition of calf serum, whereas PGF2 alpha had no effects on cell proliferation in either the presence or the absence of calf serum. Stimulation of a different clone of NIH-3T3 cells (AmNIH-3T3) or Swiss 3T3 cells with PGF2 alpha resulted in both inositol phospholipid breakdown and cell proliferation. No differences were found in the characteristics of PGF2 alpha-stimulated inositol phosphate generation between the two clones of NIH-3T3 cells, nor was there any difference in receptor number of Kd. These results question the role of inositol phospholipid breakdown in mitogenesis and demonstrate significant differences in the biochemical properties of apparently the 'same' cells.
Collapse
Affiliation(s)
- F M Black
- Department of Biochemistry, University of Glasgow, Scotland, U.K
| | | |
Collapse
|
34
|
Rodan SB, Wesolowski G, Yoon K, Rodan GA. Opposing Effects of Fibroblast Growth Factor and Pertussis Toxin on Alkaline Phosphatase, Osteopontin, Osteocalcin, and Type I Collagen mRNA Levels in ROS 17/2.8 Cells. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)47201-3] [Citation(s) in RCA: 133] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
35
|
van Corven EJ, Groenink A, Jalink K, Eichholtz T, Moolenaar WH. Lysophosphatidate-induced cell proliferation: identification and dissection of signaling pathways mediated by G proteins. Cell 1989; 59:45-54. [PMID: 2551506 DOI: 10.1016/0092-8674(89)90868-4] [Citation(s) in RCA: 672] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Lysophosphatidate (LPA), the simplest natural phospholipid, is highly mitogenic for quiescent fibroblasts. LPA-induced cell proliferation is not dependent on other mitogens and is blocked by pertussis toxin. LPA initiates at least three separate signaling cascades: activation of a pertussis toxin-insensitive G protein mediating phosphoinositide hydrolysis with subsequent Ca2+ mobilization and stimulation of protein kinase C; release of arachidonic acid in a GTP-dependent manner, but independent of prior phosphoinositide hydrolysis; and activation of a pertussis toxin-sensitive Gi protein mediating inhibition of adenylate cyclase. The peptide bradykinin mimics LPA in inducing the first two responses but fails to activate Gi and to stimulate DNA synthesis. Our data suggest that the mitogenic action of LPA occurs through Gi or a related pertussis toxin substrate and that the phosphoinositide hydrolysis-protein kinase C pathway is neither required nor sufficient, by itself, for mitogenesis. The results further suggest that LPA or LPA-like phospholipids may have a novel role in G protein-mediated signal transduction.
Collapse
Affiliation(s)
- E J van Corven
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, Amsterdam
| | | | | | | | | |
Collapse
|
36
|
Athari A, Jungermann K. Direct activation by prostaglandin F2 alpha but not thromboxane A2 of glycogenolysis via an increase in inositol 1,4,5-trisphosphate in rat hepatocytes. Biochem Biophys Res Commun 1989; 163:1235-42. [PMID: 2551282 DOI: 10.1016/0006-291x(89)91110-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In rat liver prostaglandin F2 alpha (PGF2 alpha) and thromboxane A2 (TXA2), released from non-parenchymal cells, have been implicated as mediators of the enhancement of glucose and lactate output from parenchymal cells caused by sympathetic nerve stimulation [Iwai, M. et al. (1988) Eur. J. Biochem. 175, 45-50]. In isolated rat hepatocytes PGF2 alpha, of which 75% were degraded within 10 min, but not the TXA2 analogue U46619 increased inositol 1,4,5-trisphosphate (IP3), glycogen phosphorylase a activity and glucose output like noradrenaline and vasopressin; cyclic AMP remained unaltered. The maximal increase in IP3 was reached within 20 s and in phosphorylase activity as well as glucose release within 1 min. The results indicate that only PGF2 alpha but not TXA2 can play a role as a direct mediator of the sympathetic metabolic nerve actions in rat liver and that hepatocytes contain also stimulatory prostaglandin receptors linked to phospholipase C in addition to the inhibitory receptors linked to adenylate cyclase known thus far.
Collapse
|
37
|
Susa M, Olivier AR, Fabbro D, Thomas G. EGF induces biphasic S6 kinase activation: late phase is protein kinase C-dependent and contributes to mitogenicity. Cell 1989; 57:817-24. [PMID: 2541925 DOI: 10.1016/0092-8674(89)90796-4] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Detailed kinetics reveal that EGF-induced S6 kinase activation is biphasic: an early phase appears at 10-15 min, followed by a late phase between 30 and 60 min. Both activities exhibit the same chromatographic behavior and sensitivity to phosphatase 2A. Direct activation of protein kinase C by TPA induces only late phase activity. Down-regulation of protein kinase C leads to loss of both TPA- and EGF-induced late phase activity, while the early phase is unaffected. The loss of late phase kinase activity results in decreased EGF-induced S6 phosphorylation, protein synthesis, and cell growth. The results indicate that EGF differentially regulates S6 kinase activation by two distinct signaling pathways and that loss of the late or protein kinase C-dependent phase leads to a diminished mitogenic response.
Collapse
Affiliation(s)
- M Susa
- Friedrich Miescher Institut, Basel, Switzerland
| | | | | | | |
Collapse
|
38
|
Brown KD, Blakeley DM, Brigstock DR. Stimulation of polyphosphoinositide hydrolysis in Swiss 3T3 cells by recombinant fibroblast growth factors. FEBS Lett 1989; 247:227-31. [PMID: 2541014 DOI: 10.1016/0014-5793(89)81340-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mitogenic concentrations of recombinant acidic or basic fibroblast growth factor (FGF) stimulated the accumulation of [3H]inositol phosphates ([3H]IPs) in Swiss 3T3 cells pre-labelled for 48 h with [3H]inositol. Maximal effects were obtained at 0.3 ng/ml and 3 ng/ml for basic and acidic FGF, respectively. Higher doses of either factor led to a diminished stimulation. FGF also stimulated 45Ca2+ release from cells pre-labelled with the isotope. However, FGF-stimulated production of [3H]IPs and release of 45Ca2+ exhibited marked differences when compared with the responses to the peptide mitogen bombesin; the FGF responses were markedly slower and were not inhibited by phorbol esters.
Collapse
Affiliation(s)
- K D Brown
- Department of Biochemistry, AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, England
| | | | | |
Collapse
|
39
|
Whitman M, Cantley L. Phosphoinositide metabolism and the control of cell proliferation. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 948:327-44. [PMID: 2537660 DOI: 10.1016/0304-419x(89)90005-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- M Whitman
- Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138
| | | |
Collapse
|
40
|
Trepel JB, Moyer JD, Heikkila R, Sausville EA. Modulation of bombesin-induced phosphatidylinositol hydrolysis in a small-cell lung-cancer cell line. Biochem J 1988; 255:403-10. [PMID: 2849413 PMCID: PMC1135242 DOI: 10.1042/bj2550403] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bombesin is an amphibian tetradecapeptide whose mammalian homologue, gastrin-releasing peptide (GRP), is produced by many small-cell lung-cancer (SCLC) cells, and which can function in an autocrine growth-promoting manner in SCLC. Studies reported here show that [Tyr4]bombesin and its congeners increase inositol 1,4,5-trisphosphate within seconds in NCI-H345, a SCLC cell line that constitutively produces GRP. After 30 min in the presence of 0.01 M-Li+ and [Tyr4]bombesin, there is marked accumulation of inositol monophosphates and inositol tetrakisphosphate. Pretreatment with phorbol 12-myristate 13-acetate (PMA) for 20 min inhibited the ability of [Tyr4]bombesin to induce phosphatidylinositol (PtdIns) turnover and to increase intracellular free Ca2+ ([Ca2+]i). Pretreatment with PMA for 48 h attenuated the ability of subsequently added PMA to decrease the response to [Tyr4]bombesin. Pretreatment with pertussis toxin (PT; 1 microgram/ml for 18-24 h) decreased by less than 30% [Tyr4]bombesin-induced increases in [Ca2+]i and PtdIns metabolites. However, interpretation of this result is complicated by the inability of PT to ADP-ribosylate completely its substrates in intact NCI-H345 cells. In contrast, pretreatment with cholera toxin (1 microgram/ml for 18-24 h) lowered basal [Ca2+]i and basal inositol phosphate concentrations, attenuated the response of NCI-H345 to subsequently added [Tyr4]bombesin, and was not mimicked by treatments that increase cellular cyclic AMP. These data demonstrate the activation of phospholipase C in SCLC by bombesin congeners. In addition, the results suggest a regulatory role for protein kinase C, a cholera-toxin substrate, and perhaps a pertussis-toxin substrate in the response of SCLC to bombesin.
Collapse
Affiliation(s)
- J B Trepel
- National Cancer Institute--Navy Medical Oncology Branch, Bethesda, MD 20814
| | | | | | | |
Collapse
|
41
|
Taylor CW, Blakeley DM, Brown KD. Guanine nucleotides stimulate hydrolysis of phosphatidylinositol and polyphosphoinositides in permeabilized Swiss 3T3 cells. FEBS Lett 1988; 237:163-7. [PMID: 2844585 DOI: 10.1016/0014-5793(88)80193-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hydrolysis-resistant analogues of GTP specifically stimulate the formation of [3H]inositol mono-, bis- and trisphosphates by saponin-permeabilized Swiss 3T3 cells prelabelled with [3H]inositol. Each inositol phosphate is formed largely by hydrolysis of its parent lipid and not by dephosphorylation of inositol 1,4,5-trisphosphate [(1,4,5)IP3]. Although hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) is most sensitive to guanine nucleotides, hydrolysis of phosphatidyl-inositol (PI) and phosphatidylinositol 4-phosphate (PIP) is quantitatively more important. These results suggest that a guanine nucleotide-dependent regulatory protein(s) (G-protein) is involved in regulating the hydrolysis of PI and PIP, as well as PIP2, and so may allow formation of diacylglycerol (DG) without simultaneous production of (1,4,5)IP3 and mobilization of intracellular Ca2+.
Collapse
Affiliation(s)
- C W Taylor
- AFRC Unit of Insect Neurophysiology and Pharmacology, Department of Zoology, Cambridge, England
| | | | | |
Collapse
|