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. 2006 Mar 10;8(1):E112–E117. doi: 10.1208/aapsj080113

Activation of G-proteins in brain by endogenous and exogenous cannabinoids

Steven R Childers 1,✉
PMCID: PMC2751429  PMID: 16584117

Abstract

The biological response to cannabinoid agonist begins when the agonist-bound receptor activates G-protein Gα subunits, thus initiating a cascade of signal transduction pathways. For this reason, information about cannabinoid receptors/G-protein coupling is critical to understand both the acute and chronic actions of cannabinoids. This review focuses on these mechanisms, predominantly examining the ability of cannabinoid agonists to activate G-proteins in brain with agonist-stimulated [35S]guanylyl-5′-O-(γ-thio)-triphosphate ([35S]GTPγS) binding. Acute efficacies of cannabinoid agonists at the level of G-protein activation depend not only on the ability of the agonist to induce a high affinity state in Gα for GTP, but also to induce a low affinity for GDP. When several agonists are compared, it is clear that cannabinoid agonists differ considerably in their efficacy. Both WIN 55212-2 and levonantradol are full agonists, while Δ9 is a weak partial agonist. Of interest, anandamide and its stable analog methanand amide are partial agonists. Chronic treatment in vivo with cannabinoids produces significant tolerance to the physiological and behavioral effects of these drugs, and several studies have shown that this is accompanied by a significant loss in the ability of cannabinoid receptors to couple to G-proteins in brain. These effects vary across different brain regions and are usually (but not always) accompanied by loss of cannabinoid receptor binding. Although the relationship between cannabinoid receptor desensitization and tolerance has not yet been established, these mechanisms may represent events that lead to a loss of cannabinoid agonist response and development of tolerance.

Key words: G-protein, Efficacy, Signal transduction, Anandamide, Delta-9-tetrahydrocannibinol, Levonantradol, Desensitization

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References

  • 1.Howlett AC. Inhibition of neuroblastoma adenylyl cyclase by cannabinoid and nantradol compounds. Life Sci. 1984;35:1803–1810. doi: 10.1016/0024-3205(84)90278-9. [DOI] [PubMed] [Google Scholar]
  • 2.Howlett AC, Fleming RM. Cannabinoid inhibition of adenylate cyclase: pharmacology of the response in neuroblastoma cell membranes. Mol Pharmacol. 1984;26:532–538. [PubMed] [Google Scholar]
  • 3.Howlett AC. Cannabinoid inhibition of adenylate cyclase: biochemistry of the response in neuroblastoma cell membranes. Mol Pharmacol. 1985;27:429–436. [PubMed] [Google Scholar]
  • 4.Howlett AC, Qualy JM, Khachatrian LL. Involvement of Gi in the inhibition of adenylate cyclase by cannabimimetic drugs. Mol Pharmacol. 1986;29:307–313. [PubMed] [Google Scholar]
  • 5.Devane WA, Dysarz FAI, Johnson MR, Melvin LS, Howlett AC. Determination and characterization of a cannabinoid receptor in rat brain. Mol Pharmacol. 1988;34:605–613. [PubMed] [Google Scholar]
  • 6.Herkenham M, Lynn AB, Johnson MR, Melvin LS, de Costa BR, Rice KC. Characterization and localization of cannabinoid receptors in rat brain: a quantitative in vitro autoradiographic study. J Neurosci. 1991;11:563–583. doi: 10.1523/JNEUROSCI.11-02-00563.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Matsuda LA, Lolait SJ, Brownstein MJ, Young AL, Bonner TI. Structure of a cannabinoid receptor and functional expression of the cloned cDNA. Nature. 1990;346:561–564. doi: 10.1038/346561a0. [DOI] [PubMed] [Google Scholar]
  • 8.Munro S, Thomas KL, Abu-Shaar M. Molecular characterization of a peripheral receptor for cannabinoids. Nature. 1993;365:61–65. doi: 10.1038/365061a0. [DOI] [PubMed] [Google Scholar]
  • 9.Devane WA, Hanus L, Breuer A, et al. Isolation and structure of a brain constituent that binds to the cannabinoid receptor. Science. 1992;258:1946–1949. doi: 10.1126/science.1470919. [DOI] [PubMed] [Google Scholar]
  • 10.Mechoulam R, Ben-Shabat S, Hanus L, et al. Identification of an endogenous 2-monoglyceride, present in canine gut, that binds to cannabinoid receptors. Biochem Pharmacol. 1995;50:83–90. doi: 10.1016/0006-2952(95)00109-D. [DOI] [PubMed] [Google Scholar]
  • 11.Houston DB, Howlett AC. Solubilization of the cannabinoid receptor from rat brain and its functional interaction with guanine nucleotide-binding proteins. Mol Pharmacol. 1993;43:17–22. [PubMed] [Google Scholar]
  • 12.Mukhopadhyay S, Howlett AC. Chemically distinct ligands promote differential CB1 cannabinoid receptor-Gi protein interactions. Mol Pharmacol. 2005;67:2016–2024. doi: 10.1124/mol.104.003558. [DOI] [PubMed] [Google Scholar]
  • 13.Selley DE, Stark S, Sim LJ, Childers SR. Cannabinoid receptor stimulation of guanosine-5′-O-(3-[35S]thio)triphosphate binding in rat brain membranes. Life Sci. 1996;59:659–668. doi: 10.1016/0024-3205(96)00347-5. [DOI] [PubMed] [Google Scholar]
  • 14.Kurose H, Katada T, Haga T, Haga K, Ichiyama A, Ui M. Functional interaction of purified muscarinic receptors with purified inhibitory guanine nucleotide regulatory proteins reconstituted in phospholipid vesicles. J Biol Chem. 1986;261:6423–6428. [PubMed] [Google Scholar]
  • 15.Florio VA, Sternweiss PC. Mechanisms of muscarinic receptor action on Go in reconstituted phospholipid vesicles. J Biol Chem. 1989;264:3909–3915. [PubMed] [Google Scholar]
  • 16.Asano T, Pedersen SE, Scott CW, Ross EM. Reconstitution of catecholamine-stimulated binding of guanosine 5′-O-(3-thiotriphosphate) to the stimulatory GTP-binding protein of adenylate cyclase. Biochemistry. 1984;23:5460–5467. doi: 10.1021/bi00318a013. [DOI] [PubMed] [Google Scholar]
  • 17.Hilf G, Gierschik P, Jakobs KH. Muscarinic acetylcholine receptor-stimulated binding of guanosine 5′-O-(3-thiotriphosphate) to guanine-nucleotide-binding proteins in cardiac membranes. Eur J Biochem. 1989;186:725–731. doi: 10.1111/j.1432-1033.1989.tb15266.x. [DOI] [PubMed] [Google Scholar]
  • 18.Lorenzen A, Fuss M, Vogt H, Schwabe U. Measurement of guanine nucleotide-binding protein activation by A1 adenosine receptor agonists in bovine brain membranes: stimulation of guanosine-5′-O-(3-[35S]thio)triphosphate binding. Mol Pharmacol. 1993;44:115–123. [PubMed] [Google Scholar]
  • 19.Lazareno S, Farries T, Birdsall NJM. Pharmacological characterization of guanine nucleotide exchange reactions in membranes from CHO cells stably transfected with human muscarinic receptors M1–M4. Life Sci. 1993;52:449–456. doi: 10.1016/0024-3205(93)90301-I. [DOI] [PubMed] [Google Scholar]
  • 20.Levy FO, Zhu X, Kaumann AJ, Birnbaumer L. Efficacy of β1-adrenergic receptors is lower than that of β2-adrenergic receptors. Proc Natl Acad Sci USA. 1993;90:10798–10802. doi: 10.1073/pnas.90.22.10798. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21.Birnbaumer L, Levy FO, Zhu X, Kaumann AJ. Studies on the intrinsic activity (efficacy) of human adrenergic receptors. Tex Heart Inst. J. 1994;21:16–21. [PMC free article] [PubMed] [Google Scholar]
  • 22.Breivogel CS, Selley DE, Childers SR. Acute and chronic effects of opioids on delta and mu receptor activation of G-proteins in NG108-15 and SK-N-SH cell membranes. J Neurochem. 1997;68:1462–1472. doi: 10.1046/j.1471-4159.1997.68041462.x. [DOI] [PubMed] [Google Scholar]
  • 23.Sim LJ, Selley DE, Childers SR. In vitro autoradiography of receptor-activated G-proteins in rat brain by agonist-stimulated guanylyl 5′-[γ-[35S]thio]-triphosphate binding. Proc Natl Acad Sci USA. 1995;92:7242–7246. doi: 10.1073/pnas.92.16.7242. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24.Breivogel CS, Selley DE, Childers SR. Cannabinoid receptor agonist efficacy for stimulating [35S]GTPγS binding to rat cerebellar membranes correlates with agonist-induced decreases in GDP affinity. J Biol Chem. 1998;273:16865–16873. doi: 10.1074/jbc.273.27.16865. [DOI] [PubMed] [Google Scholar]
  • 25.Kuster J, Stevenson J, Ward S, D'Ambra T, Haycock D. Aminoalkylindole binding in rat cerebellum: selective displacement by natural and synthetic cannabinoids. J Pharmacol Exp Ther. 1993;264:1352–1363. [PubMed] [Google Scholar]
  • 26.Sim LJ, Selley DE, Xiao R, Childers SR. Differences in G-protein activation by mu and delta opioid, and cannabinoid, receptors in rat striatum. Eur J Pharmacol. 1996;307:97–105. doi: 10.1016/0014-2999(96)00211-7. [DOI] [PubMed] [Google Scholar]
  • 27.Breivogel CS, Sim LJ, Childers SR. Regional differences in cannabinoid receptor/G-protein coupling in rat brain. J Pharmacol Exp Ther. 1997;282:1632–1642. [PubMed] [Google Scholar]
  • 28.Selley DE, Sim LJ, Xiao R, Liu Q, Childers SR. Mu opioid receptor-stimulated [35S]GTPγS binding in rat thalamus and cultured cell lines: signal transduction mechanisms underlying agonist efficacy. Mol Pharmacol. 1997;51:87–96. doi: 10.1124/mol.51.1.87. [DOI] [PubMed] [Google Scholar]
  • 29.Burkey TH, Quock RM, Consroe P, et al. Relative efficacies of cannabinoid CB1 receptor agonists in the mouse brain. Eur J Pharmacol. 1997;336:295–298. doi: 10.1016/S0014-2999(97)01255-7. [DOI] [PubMed] [Google Scholar]
  • 30.Sim LJ, Hampson RE, Deadwyler SA, Childers SR. Effects of chronic treatment with Δ9-tetrahydrocannabinol on cannabinoid-stimulated [35S]GTPγS autoradiography in rat brain. J Neurosci. 1996;16:8057–8066. doi: 10.1523/JNEUROSCI.16-24-08057.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Childers SR, Sexton T, Roy MB. Effects of anandamide on cannabinoid receptors in rat brain membranes. Biochem. Pharmacol. 1994;47:711–715. doi: 10.1016/0006-2952(94)90134-1. [DOI] [PubMed] [Google Scholar]
  • 32.Mackie K, Devane WA, Hille B. Anandamide, an endogenous cannabinoid, inhibits calcium currents as a partial agonist in N18 neuroblastoma cells. Mol Pharmacol. 1993;44:498–503. [PubMed] [Google Scholar]
  • 33.Shen M, Piser TM, Seybold VS, Thayer SA. Cannabinoid receptor agonists inhibit glutamatergic synaptic transmission in rat hippocampal cultures. J Neurosci. 1996;16:4322–4334. doi: 10.1523/JNEUROSCI.16-14-04322.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Landsman RS, Burkey TH, Consroe P, Roeske WR, Yamamura HI. SR141716A is an inverse agonist at the human cannabinoid CB1 receptor. Eur J Pharmacol. 1997;334:R1–R2. doi: 10.1016/S0014-2999(97)01160-6. [DOI] [PubMed] [Google Scholar]
  • 35.Felder CC, Joyce KE, Briley EM, et al. Comparison of the pharmacology and signal transduction of the human cannabinoid CB1 and CB2 receptors. Mol Pharmacol. 1995;48:443–450. [PubMed] [Google Scholar]
  • 36.Pacheco M, Ward SJ, Childers SR. Identification of cannabinoid receptors in cultures of rat cerebellar granule cells. Brain Res. 1993;603:102–110. doi: 10.1016/0006-8993(93)91304-B. [DOI] [PubMed] [Google Scholar]
  • 37.Bidaut-Russell M, Devane WA, Howlett AC. Cannabinoid receptors and modulation of cyclic AMP accumulation in the rat brain. J Neurochem. 1990;55:21–26. doi: 10.1111/j.1471-4159.1990.tb08815.x. [DOI] [PubMed] [Google Scholar]
  • 38.Glass M, Felder CC. Concurrent stimulation of cannabinoid CB1 and dopamine D2 receptors augments cAMP accumulation in striatal neurons: evidence for a Gs linkage to the CB1 receptor. J Neurosci. 1997;17:5327–5333. doi: 10.1523/JNEUROSCI.17-14-05327.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 39.Caulfield MP, Brown DA. Cannabinoid receptor agonists inhibit Ca currents in NG108-15 neuroblastoma cells via a pertussis toxin-sensitive mechanism. Br J Pharmacol. 1992;106:231–232. doi: 10.1111/j.1476-5381.1992.tb14321.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 40.Mackie K, Lai Y, Westenbroek R, Mitchell R. Cannabinoids activate an inwardly rectifying potassium conductance and inhibit Q-type calcium currents in AtT20 cells transfected with rat brain cannabinoid receptor. J Neurosci. 1995;15:6552–6561. doi: 10.1523/JNEUROSCI.15-10-06552.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 41.Diana MA, Levenes C, Mackie K, Marty A. Short-term retrograde inhibition of GABAergic synaptic currents in rat Purkinje cells is mediated by endogenous cannabinoids. J Neurosci. 2002;22:200–208. doi: 10.1523/JNEUROSCI.22-01-00200.2002. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 42.Deadwyler SA, Heyser CJ, Hampson RE. Complete adaptation to the memory disruptive effects of delta-9-THC following 35 days of exposure. Neurosci Res Commun. 1995;17:9–18. [Google Scholar]
  • 43.Abood ME, Sauss C, Fan F, Tilton CL, Martin BR. Development of behavioral tolerance to Δ9-THC without alteration of cannabinoid receptor binding or mRNA levels in whole brain. Pharmacol Biochem Behav. 1993;46:575–579. doi: 10.1016/0091-3057(93)90546-6. [DOI] [PubMed] [Google Scholar]
  • 44.Adams IB, Martin BR. Cannabis: pharmacology and toxicology in animals and humans. Addiction. 1996;91:1585–1614. doi: 10.1111/j.1360-0443.1996.tb02264.x. [DOI] [PubMed] [Google Scholar]
  • 45.Fan F, Tao Q, Abood ME, Martin BR. Cannabinoid receptor down-regulation without alteration of the inhibitory effect of CP 55,940 on adenylyl cyclase in the cerebellum of CP 55,940-tolerant mice. Brain Res. 1996;706:13–20. doi: 10.1016/0006-8993(95)01113-7. [DOI] [PubMed] [Google Scholar]
  • 46.Rodriguez de Fonseca F, Gorriti MA, Fernandez-Ruiz JJ, Palomo T, Ramos JA. Downregulation of rat brain cannabinoid binding sites after chronic Δ9-tetrahydrocannabinol treatment. Pharmacol Biochem Behav. 1994;47:33–40. doi: 10.1016/0091-3057(94)90108-2. [DOI] [PubMed] [Google Scholar]
  • 47.Romero J, Garciá L, Fernández-Ruiz JJ, Cebeira M, Ramos JA. Changes in rat brain cannabinoid binding sites after acute or chronic exposure to their endogenous agonist, anandamide, or to Δ9-tetrahydrocannabinol. Pharmacol Biochem Behav. 1995;51:731–737. doi: 10.1016/0091-3057(95)00023-P. [DOI] [PubMed] [Google Scholar]
  • 48.Coutts AA, Anavi-Goffer S, Ross RA, et al. Agonist-induced internalization and trafficking of cannabinoid CB1 receptors in hippocampal neurons. J Neurosci. 2001;21:2425–2433. doi: 10.1523/JNEUROSCI.21-07-02425.2001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 49.Breivogel CS, Childers SR, Deadwyler SA, Hampson RE, Vogt LJ, Sim-Selley LJ. Chronic Δ9-tetrahydrocannabinol produces a time-dependent loss of cannabinoid receptors and cannabinoid receptor-activated G-proteins in rat brain. J Neurochem. 1999;73:2447–2459. doi: 10.1046/j.1471-4159.1999.0732447.x. [DOI] [PubMed] [Google Scholar]
  • 50.Breivogel CS, Scates SM, Beletskaya IO, Lowery OB, Aceto MD, Martin BR. The effects of delta9-tetrahydrocannabinol physical dependence on brain cannabinoid receptors. Eur J Pharmacol. 2003;459:139–150. doi: 10.1016/S0014-2999(02)02854-6. [DOI] [PubMed] [Google Scholar]
  • 51.Sim-Selley LJ, Martin BR. Effect of chronic administration of R-(+)-[2,3-Dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl) methanone mesylate (WIN55,212-2) or delta(9)-tetrahy drocannabinol on cannabinoid receptor adaptation in mice. J Pharmacol Exp Ther. 2002;303:36–44. doi: 10.1124/jpet.102.035618. [DOI] [PubMed] [Google Scholar]
  • 52.Corchero J, Romero J, Berrendero F, et al. Time-dependent differences of repeated administration with Delta9-tetrahydrocannabinol in proenkephalin and cannabinoid receptor gene expression and G-protein activation by mu-opioid and CB1-cannabinoid receptors in the caudate-putamen. Brain Res Mol Brain Res. 1999;67:148–157. doi: 10.1016/S0169-328X(99)00053-4. [DOI] [PubMed] [Google Scholar]
  • 53.Rubino T, Vigano D, Costa B, Colleoni M, Parolaro D. Loss of cannabinoid-stimulated guanosine 5′-O-(3-[(35)S]thiotriphosphate) binding without receptor down-regulation in brain regions of anandamide-tolerant rats. J Neurochem. 2000;75:2478–2484. doi: 10.1046/j.1471-4159.2000.0752478.x. [DOI] [PubMed] [Google Scholar]
  • 54.Sim-Selley LJ. Regulation of cannabinoid CB1 receptors in the central nervous system by chronic cannabinoids. Crit Rev Neurobiol. 2003;15:91–119. doi: 10.1615/CritRevNeurobiol.v15.i2.10. [DOI] [PubMed] [Google Scholar]

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