Hostname: page-component-848d4c4894-mwx4w Total loading time: 0 Render date: 2024-07-02T21:03:50.982Z Has data issue: false hasContentIssue false

Guanine-nucleotide binding regulatory proteins as targets for novel drugs

Published online by Cambridge University Press:  05 December 2011

N. J. Pyne
Affiliation:
Department of Physiology & Pharmacology, University of Strathclyde, Royal College, 204 George Street, Glasgow Gl 1XW, U.K.
Get access

Summary:

Guanine-nucleotide regulatory binding proteins (G-proteins) serve to transduce information from agonist-bound receptor complexes to either effector enzymes or ion-channels. Drugs that perturb the function of G-proteins may do so by one of four mechanisms, (i) They may exert negative intrinsic activity toward the G-protein. For instance, we have shown that incubation of isolated plasma-membranes with the β-adrenoceptor blocking drug sotalol blocked both GTP-stimulated and isoprenaline-stimulated adenylyl cyclase. This suggests that the empty β-adrenoceptor is capable of tonically stimulating G, and therefore adenylyl cyclase; that is, empty β-adrenoceptors promote GDP-GTP exchange, (ii) They may perturb the GDP-GTP exchange reaction. For instance, certain PDE inhibitors, including SKF 94836 and rolipram, stimulate a marked increase in the pertussis toxin-catalysed NAD+-dependent ADP-ribosylation of G. This effect is similar to that of GDP, which promotes stabilisation of the αβγ holomer of Gi. The effect of these PDE inhibitors is completely reversed by GppNHp, which triggers afly dissociation by binding to the guanine-nucleotide binding domain of the G-protein. PDE inhibitors may serve as a class of drugs which perturb GDP-GTP exchange, (iii) They may trigger uncoupling of receptor-G-protein complexes. For instance, the polycationic drug mastoparan binds to the C-terminal end of the G-protein and mimics the effect of receptor activation by promoting GTP-γ-S binding, a reduction in pertussis toxin-catalysed ADP-ribosylation, and inhibition of adenylyl cyclase activity. Other agents, such as polyanionic drugs, bind to the receptor to promote uncoupling of receptor-mediated activation of certain G-proteins. (iv) They may alter the cross-talk mechanisms that operate between different receptor signalling systems. For instance, protein kinase C promotes the phosphorylation and inactivation of Gi. This leads to an unopposed stimulation of adenylyl cyclase via Gs and, therefore, enhanced sensitivity to agents such as glucagon. Protein kinase C inhibitors may be usefully exploited to modulate these processes which appear to be abberant in certain disease states.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aktories, K., & Jakobs, K. H., 1981. Epinephrine inhibits adenylate cyclase and stimulates a GTPase in human platelet membranes via α-adrenoceptors. Federation of the European Biochemical Society Letters 130, 235–8.CrossRefGoogle ScholarPubMed
Berridge, M. J., & Irvine, R. F., 1984. Inositol trisphosphate, a novel second-messenger in cellular signal transduction. Nature 312, 315–21.CrossRefGoogle ScholarPubMed
Birnbaumer, L., 1990. Transduction of receptor signal into modulation of effector activity by G-proteins: the first 20 years or so. FASEB Journal 4, 3178–88.CrossRefGoogle ScholarPubMed
Bourne, H. R., Sanders, D. A., & McCormick, F., 1991. The GTPase superfamily: conserved structure and molecular mechanism. Nature 349, 117–26.CrossRefGoogle ScholarPubMed
Bushfield, M., Pyne, N. J., & Houslay, M. D., 1990a. Changes to the phosphorylation state of the inhibitory G-protein Gi2 in hepatocytes from lean (FA/FA) and obese (OB/OB) Zucker rats. European Journal of Biochemistry 192, 537–42.CrossRefGoogle Scholar
Bushfield, M., Griffiths, S. L., Murphy, G. J., Pyne, N. J., Knowler, J. T., Milligan, G., Parker, P. J., Mollner, S., & Houslay, M. D., 1990b. Diabetes-induced alterations in the expression, functioning and phosphorylation state of the inhibitory guanine-nucleotide regulatory protein Gi2 in hepatocytes. Biochemical Journal 271, 365–72.CrossRefGoogle ScholarPubMed
Butler, S. J., Kelly, E., McKenzie, F., Guild, S., Wakelam, R. J. O., & Milligan, G., 1988. Differential effects of suramin on the coupling of receptors to individual species of pertussis toxin sensitive guanine nucleotide binding proteins. Biochemical Journal 251, 201–5.CrossRefGoogle ScholarPubMed
Cassel, D., & Selinger, Z., 1976. Catecholamine-stimulated GTPase activity in turkey erthrocyte membranes. Biochemical Biophysical Acta 452, 538–51.CrossRefGoogle Scholar
Codina, J., Hildebrandt, J. D., Birnbaumer, L., & Sejura, R. D., 1984. Effects of guanine nucleotides and Mg on human erthrocyte Ni and Ns, the regulatory components of adenylate cyclase. Journal of Biological Chemistry 259, 11408–18.CrossRefGoogle Scholar
Feldman, A. M., Cates, A. E., Veazey, W. R., Hecshberger, R. E., Bristow, M. R., Buaghman, K. L., Buamgaster, W. A., & Van Dop, C., 1988. Increase of the 40 kDa mol wt pertussis substrate in failing human heart. Journal of Clinical Investigation 82, 189–97.CrossRefGoogle Scholar
Gawler, D., Milligan, G., Spiegel, A. M., Unson, C. G., & Houslay, M. D., 1987. Abolition of the expression of inhibitory guanine-nucleotide regulatory protein, Gi activity in diabetes. Nature 327, 229–32.CrossRefGoogle ScholarPubMed
Gierschik, P., Milligan, G., Pines, M., Goldsmith, P., Codina, J., Klee, N., & Spiegel, A., 1986. Use of specific antibodies to quantitate the guanine-nucleotide binding protein, Go, in brain. Proceedings of the National Academy of Sciences U.S.A. 83, 2258–62.CrossRefGoogle ScholarPubMed
Gill, D. M., & Meren, R., 1978. ADP-ribosylation of membrane proteins catalysed by cholera toxin. Basis of the activation of adenylate cyclase. Proceedings of the National Academy of Sciences U.S.A. 75, 3050–4.CrossRefGoogle Scholar
Gilman, A. G., 1987. G-proteins, transducers of receptor generated signals. Annual Review of Biochemistry 56, 615–49.CrossRefGoogle ScholarPubMed
Higashijima, T., Ferguson, K. M., Sternweiss, P. C., Smigel, N. D., & Gilman, A. G., 1987. Effects of Mg2+ and the beta-gamma sub-unit complex on the interaction of guanine-nucleotides with G-proteins. Journal of Biological Chemistry 262, 762–6.CrossRefGoogle Scholar
Higashijima, T., Uzu, S., Nakajima, T., & Ross, E. M., 1988. Mastoparan, a peptide from wasp venom, mimics receptors by activating GTP-binding regulatory proteins. Journal of Biological Chemistry 263, 6491–4.CrossRefGoogle ScholarPubMed
Huang, R. R., Dehaven, R. N., Cheung, A. H., Diehl, R. E., Dixon, R. A. F., & Strader, C. D., 1990. Identification of allosteric antagonists of receptor-guanine nucleotide-binding protein interactions. Molecular Pharmacology 37, 304–10.Google ScholarPubMed
Itoh, M., Toyana, R., Kozasa, T., Tsutamoto, T., Matsuoka, M., & Kaziio, Y., 1988. Presence of three distinct molecular species of Gi protein α sub-unit. Journal of Biological Chemistry 263, 6656–64.CrossRefGoogle Scholar
Jelsema, C. L., & Axelrod, J., 1987. Stimulation of phospholipase A2 activity in bovine rod outer segments by the βγ sub-units of transducin and the inhibition by the α sub-unit. Proceedings of the National Academy of Sciences 80, 3899–902.Google Scholar
Katada, T., Gilman, A. G., Watanabe, Y., Bauhr, S., & Jakobs, K. H., 1985. Protein kinase C phosphorylates the inhibitory guanine-nucleotide-binding regulatory component and apparently suppresses the function in hormonal inhibition of adenylate cyclase. European Journal of Biochemistry 151, 431–7.CrossRefGoogle ScholarPubMed
Klinz, F. J., & Costa, T., 1989. Cholera toxin ADP ribosylates the receptor-coupled form of pertussis toxin-sensitive G-proteins. Biochemical Biophysical Research Communications 165, 554–60.CrossRefGoogle ScholarPubMed
Londos, C., Salomon, Y., Lin, M. C., Harwood, J. P., Schramm, M., Wolff, J., & Rodbell, M., 1974. 5′-Guanylyl-imidodiphosphate, a potent activator of adenylate cyclase systems in eukaryotic cells. Proceedings of the National Academy of Sciences U.S.A. 71, 3087–90.CrossRefGoogle Scholar
Longabaugh, J. P., Vatner, D. E., Vatner, S. F., & Homly, C. J., 1988. Decreased stimulatory guanosine triphosphate binding protein in dogs with pressure overload left ventricular failure. Journal of Clinical Investigation 81, 420–4.CrossRefGoogle ScholarPubMed
Masters, S. B., Stroud, R. M., & Bourne, H. R., 1986. Family of G-proteins a chains. Amphiphatic analysis and predicted structural domains. Protein Engineering 1, 4754.CrossRefGoogle Scholar
Masters, S. B., Sullivan, K. A., Beiderman, B., Ramachandran, J., & Bourne, H. R., 1988. The carboxy-terminal domain of G, specifies coupling of receptor to stimulation of adenylate cyclase. Science 241, 448–51.CrossRefGoogle Scholar
McKenzie, F. R., & Milligan, G., 1990. σ-opioid-receptor mediated inhibition of adenylate cyclase is transduced specifically by the guanine-nucleotide regulatory protein, Gi2. Biochemical Journal 267, 391–8.CrossRefGoogle Scholar
Milligan, G., Spiegel, A. M., Unsun, C. G., & Saggerson, E. D., 1987. Chemically induced hypothyroidism produces elevated levels of the alpha sub-unit of the inhibitory guanine nucleotide protein (Gi) and the beta sub-unit common to all G-proteins. Biochemical Journal 247, 223–7.CrossRefGoogle Scholar
Neer, E. J., & Clapham, D. C., 1988. The role of G-protein sub-units in transmembrane signalling. Nature 333, 129–34.CrossRefGoogle Scholar
Nishizuka, Y., 1984. The molecular heterogeneity of protein kinase C and the implications for cellular regulation. Nature 308, 693–8.CrossRefGoogle Scholar
Parsons, W. J., Ramkumar, V., & Stiles, G., 1988a. Isobutylmethylxanthine stimulates adenylate cyclase by blocking the inhibitory regulatory protein, Gi. Molecular Pharmacology 34, 3741.Google ScholarPubMed
Parsons, W. J., Ramkumar, V., & Stiles, G., 1988b. The new cardiotonic agent sulmazole is an A1, adenosine receptor antagonist and functionally blocks the inhibitory regulator, Gi. Molecular Pharmacology 33, 441–8.Google ScholarPubMed
Pyne, N. J., Murphy, G. J., Milligan, G., & Houslay, M. D., 1989. Treatment of intact hepatocytes with either TPA or glucagon elicits the phosphorylation and functional inactivation of the inhibitory guanine-nucleotide regulatory protein Gi. Federation of European Biochemical Societies Letters B243, 7782.CrossRefGoogle Scholar
Rail, T., & Harris, B. A., 1987. Identification of the lesion in the stimulatory GTP-binding protein of uncoupled S49 lymphoma. Federation of European Biochemical Societies Letters 224, 365371.CrossRefGoogle Scholar
Salomon, Y., Lin, M. C., Londas, C., Rendell, M., & Rodbell, M., 1975. The hepatic adenylate cyclase system I. Evidence for transition sites and structural requirements for guanine nucleotide activation. Journal of Biological Chemistry 250, 4239–45.CrossRefGoogle Scholar
Simonds, W. F., Goldsmith, P. K., Codina, J., Unson, C. G., & Spiegel, A. M., 1989. Gi2 mediates α2-adrenergic inhibition of adenylate cyclase in platelet membranes. In situ identification with T,α C-terminal antibodies. Proceedings of the National Academy of Sciences 86, 7809–13.CrossRefGoogle Scholar
Sullivan, K. A., Miller, R. J., Masters, S. B., Berderman, B., Heideman, W., & Bourne, H. R., 1987. Identification of receptor contact site involved in receptor-G-protein coupling. Nature 330, 658759.CrossRefGoogle ScholarPubMed
Taylor, C. W., 1990. The role of G-proteins in transmembrane signalling. Biochemical Journal 111, 113.CrossRefGoogle Scholar
Valler, I., Spada, A., & Gianattasio, G., 1987. Altered Gs and adenylate cyclase activity in human GH-secreting pituitary adenomas. Nature 330, 566–8.CrossRefGoogle Scholar