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. 1996 Feb 15;491(Pt 1):151–161. doi: 10.1113/jphysiol.1996.sp021203

Neuronal nicotinic alpha 7 receptor expressed in Xenopus oocytes presents five putative binding sites for methyllycaconitine.

E Palma 1, S Bertrand 1, T Binzoni 1, D Bertrand 1
PMCID: PMC1158766  PMID: 9011607

Abstract

1. The recently isolated compound methyllycaconitine (MLA) is a plant toxin which is a competitive inhibitor of nicotinic acetylcholine receptors (nAChRs). We found that homomeric alpha 7 receptors display a very high sensitivity to MLA with an IC50 in the picomolar range. 2. The competitive nature of the alpha 7 MLA blockade was reinforced by the observation that this compound has no action on wild-type serotoninergic receptors (5-HT3), whereas it is a powerful antagonist of chimaeric receptors alpha 7-5-HT3. 3. The time course of MLA inhibition of the wild-type (WT) alpha 7 follows a monotonic exponential decay whose time constant is proportional to the MLA concentration and could be described by a bimolecular mechanism with a forward rate constant (k+) of 2.7 x 10(7) S-1 M-1. In contrast, recovery from MLA inhibition displays an S-shaped time course that is incompatible with a simple bimolecular reaction. 4. Given the pentameric nature of the neuronal nicotinic receptors, a linear chain model, including five putative MLA binding sites corresponding to the homomeric nature of alpha 7, is proposed. 5. Both onset and recovery data obtained on the alpha 7 wild-type receptor are adequately described by this model assuming that a single MLA molecule is sufficient to block receptor function. 6. Analysis of MLA blockade and recovery of reconstituted heteromeric alpha 4 beta 2 receptors reveals, as expected, a time course compatible with only two binding sites for the toxin and, thus, further supports the validity of our model.

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Selected References

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  1. Alkondon M., Pereira E. F., Wonnacott S., Albuquerque E. X. Blockade of nicotinic currents in hippocampal neurons defines methyllycaconitine as a potent and specific receptor antagonist. Mol Pharmacol. 1992 Apr;41(4):802–808. [PubMed] [Google Scholar]
  2. Anand R., Peng X., Ballesta J. J., Lindstrom J. Pharmacological characterization of alpha-bungarotoxin-sensitive acetylcholine receptors immunoisolated from chick retina: contrasting properties of alpha 7 and alpha 8 subunit-containing subtypes. Mol Pharmacol. 1993 Nov;44(5):1046–1050. [PubMed] [Google Scholar]
  3. Balice-Gordon R. J., Lichtman J. W. Long-term synapse loss induced by focal blockade of postsynaptic receptors. Nature. 1994 Dec 8;372(6506):519–524. doi: 10.1038/372519a0. [DOI] [PubMed] [Google Scholar]
  4. Bertrand D., Ballivet M., Gomez M., Bertrand S., Phannavong B., Gundelfinger E. D. Physiological properties of neuronal nicotinic receptors reconstituted from the vertebrate beta 2 subunit and Drosophila alpha subunits. Eur J Neurosci. 1994 May 1;6(5):869–875. doi: 10.1111/j.1460-9568.1994.tb00997.x. [DOI] [PubMed] [Google Scholar]
  5. Catterall W. A. Neurotoxins that act on voltage-sensitive sodium channels in excitable membranes. Annu Rev Pharmacol Toxicol. 1980;20:15–43. doi: 10.1146/annurev.pa.20.040180.000311. [DOI] [PubMed] [Google Scholar]
  6. Chiappinelli V. A. Actions of snake venom toxins on neuronal nicotinic receptors and other neuronal receptors. Pharmacol Ther. 1985;31(1-2):1–32. doi: 10.1016/0163-7258(85)90035-x. [DOI] [PubMed] [Google Scholar]
  7. Chiappinelli V. A., Hue B., Mony L., Sattelle D. B. Kappa-bungarotoxin blocks nicotinic transmission at an identified invertebrate central synapse. J Exp Biol. 1989 Jan;141:61–71. doi: 10.1242/jeb.141.1.61. [DOI] [PubMed] [Google Scholar]
  8. Clarke P. B. Nicotinic receptors in mammalian brain: localization and relation to cholinergic innervation. Prog Brain Res. 1993;98:77–83. doi: 10.1016/s0079-6123(08)62383-3. [DOI] [PubMed] [Google Scholar]
  9. Cooper E., Couturier S., Ballivet M. Pentameric structure and subunit stoichiometry of a neuronal nicotinic acetylcholine receptor. Nature. 1991 Mar 21;350(6315):235–238. doi: 10.1038/350235a0. [DOI] [PubMed] [Google Scholar]
  10. Couturier S., Bertrand D., Matter J. M., Hernandez M. C., Bertrand S., Millar N., Valera S., Barkas T., Ballivet M. A neuronal nicotinic acetylcholine receptor subunit (alpha 7) is developmentally regulated and forms a homo-oligomeric channel blocked by alpha-BTX. Neuron. 1990 Dec;5(6):847–856. doi: 10.1016/0896-6273(90)90344-f. [DOI] [PubMed] [Google Scholar]
  11. Eiselé J. L., Bertrand S., Galzi J. L., Devillers-Thiéry A., Changeux J. P., Bertrand D. Chimaeric nicotinic-serotonergic receptor combines distinct ligand binding and channel specificities. Nature. 1993 Dec 2;366(6454):479–483. doi: 10.1038/366479a0. [DOI] [PubMed] [Google Scholar]
  12. Elgoyhen A. B., Johnson D. S., Boulter J., Vetter D. E., Heinemann S. Alpha 9: an acetylcholine receptor with novel pharmacological properties expressed in rat cochlear hair cells. Cell. 1994 Nov 18;79(4):705–715. doi: 10.1016/0092-8674(94)90555-x. [DOI] [PubMed] [Google Scholar]
  13. Ellinor P. T., Zhang J. F., Horne W. A., Tsien R. W. Structural determinants of the blockade of N-type calcium channels by a peptide neurotoxin. Nature. 1994 Nov 17;372(6503):272–275. doi: 10.1038/372272a0. [DOI] [PubMed] [Google Scholar]
  14. Groebe D. R., Dumm J. M., Abramson S. N. Irreversible inhibition of nicotinic acetylcholine receptors by the bipinnatins. Toxin activation and kinetics of receptor inhibition. J Biol Chem. 1994 Mar 25;269(12):8885–8891. [PubMed] [Google Scholar]
  15. Gross A., Abramson T., MacKinnon R. Transfer of the scorpion toxin receptor to an insensitive potassium channel. Neuron. 1994 Oct;13(4):961–966. doi: 10.1016/0896-6273(94)90261-5. [DOI] [PubMed] [Google Scholar]
  16. Kreienkamp H. J., Sine S. M., Maeda R. K., Taylor P. Glycosylation sites selectively interfere with alpha-toxin binding to the nicotinic acetylcholine receptor. J Biol Chem. 1994 Mar 18;269(11):8108–8114. [PubMed] [Google Scholar]
  17. Kukel C. F., Jennings K. R. Delphinium alkaloids as inhibitors of alpha-bungarotoxin binding to rat and insect neural membranes. Can J Physiol Pharmacol. 1994 Jan;72(1):104–107. doi: 10.1139/y94-016. [DOI] [PubMed] [Google Scholar]
  18. Loring R. H., Aizenman E., Lipton S. A., Zigmond R. E. Characterization of nicotinic receptors in chick retina using a snake venom neurotoxin that blocks neuronal nicotinic receptor function. J Neurosci. 1989 Jul;9(7):2423–2431. doi: 10.1523/JNEUROSCI.09-07-02423.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Puchacz E., Buisson B., Bertrand D., Lukas R. J. Functional expression of nicotinic acetylcholine receptors containing rat alpha 7 subunits in human SH-SY5Y neuroblastoma cells. FEBS Lett. 1994 Nov 7;354(2):155–159. doi: 10.1016/0014-5793(94)01108-7. [DOI] [PubMed] [Google Scholar]
  20. Role L. W. Diversity in primary structure and function of neuronal nicotinic acetylcholine receptor channels. Curr Opin Neurobiol. 1992 Jun;2(3):254–262. doi: 10.1016/0959-4388(92)90112-x. [DOI] [PubMed] [Google Scholar]
  21. Sargent P. B. The diversity of neuronal nicotinic acetylcholine receptors. Annu Rev Neurosci. 1993;16:403–443. doi: 10.1146/annurev.ne.16.030193.002155. [DOI] [PubMed] [Google Scholar]
  22. Wallace R. A., Jared D. W., Dumont J. N., Sega M. W. Protein incorporation by isolated amphibian oocytes. 3. Optimum incubation conditions. J Exp Zool. 1973 Jun;184(3):321–333. doi: 10.1002/jez.1401840305. [DOI] [PubMed] [Google Scholar]
  23. Ward J. M., Cockcroft V. B., Lunt G. G., Smillie F. S., Wonnacott S. Methyllycaconitine: a selective probe for neuronal alpha-bungarotoxin binding sites. FEBS Lett. 1990 Sep 17;270(1-2):45–48. doi: 10.1016/0014-5793(90)81231-c. [DOI] [PubMed] [Google Scholar]
  24. Weber M., Changeux J. P. Binding of Naja nigricollis (3H)alpha-toxin to membrane fragments from Electrophorus and Torpedo electric organs. 3. Effects of local anaesthetics on the binding of the tritiated alpha-neurotoxin. Mol Pharmacol. 1974 Jan;10(1):35–40. [PubMed] [Google Scholar]
  25. Weber M., Changeux J. P. Binding of Naja nigricollis (3H)alpha-toxin to membrane fragments from Electrophorus and Torpedo electric organs. I. Binding of the tritiated alpha-neurotoxin in the absence of effector. Mol Pharmacol. 1974 Jan;10(1):1–14. [PubMed] [Google Scholar]
  26. Weber M., Changeux J. P. Binding of Naja nigricollis (3H)alpha-toxin to membrane fragments from Electrophorus and Torpedo electric organs. II. Effect of cholinergic agonists and antagonists on the binding of the tritiated alpha-neurotoxin. Mol Pharmacol. 1974 Jan;10(1):15–34. [PubMed] [Google Scholar]
  27. de la Garza R., Freedman R., Hoffer B. J. Kappa-bungarotoxin blockade of nicotine electrophysiological actions in cerebellar Purkinje neurons. Neurosci Lett. 1989 Apr 24;99(1-2):95–100. doi: 10.1016/0304-3940(89)90271-1. [DOI] [PubMed] [Google Scholar]

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