Skip to main content
PMC home page
The Journal of General Physiology logoLink to The Journal of General Physiology
. 1995 Jun 1;105(6):745–764. doi: 10.1085/jgp.105.6.745

Regions of beta 2 and beta 4 responsible for differences between the steady state dose-response relationships of the alpha 3 beta 2 and alpha 3 beta 4 neuronal nicotinic receptors

PMCID: PMC2216958  PMID: 7561742

Abstract

We constructed chimeras of the rat beta 2 and beta 4 neuronal nicotinic subunits to locate the regions that contribute to differences between the acetylcholine (ACh) dose-response relationships of the alpha 3 beta 2 and alpha 3 beta 4 receptors. Expressed in Xenopus oocytes, the alpha 3 beta 2 receptor displays an EC50 for ACh approximately 20-fold less than the EC50 of the alpha 3 beta 4 receptor. The apparent Hill slope (n(app)) of alpha 3 beta 2 is near one whereas the alpha 3 beta 4 receptor displays an n(app) near two. Substitutions within the first 120 residues convert the EC50 for ACh from one wild-type value to the other. Exchanging just beta 2:104-120 for the corresponding region of beta 4 shifts the EC50 of ACh dose-response relationship in the expected direction but does not completely convert the EC50 of the dose- response relationship from one wild-type value to the other. However, substitutions in the beta 2:104-120 region do account for the relative sensitivity of the alpha 3 beta 2 receptor to cytisine, tetramethylammonium, and ACh. The expression of beta 4-like (strong) cooperativity requires an extensive region of beta 4 (beta 4:1-301). Relatively short beta 2 substitutions (beta 2:104-120) can reduce cooperativity to beta 2-like values. The results suggest that amino acids within the first 120 residues of beta 2 and the corresponding region of beta 4 contribute to an agonist binding site that bridges the alpha and beta subunits in neuronal nicotinic receptors.

Full Text

The Full Text of this article is available as a PDF (1.2 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Blount P., Merlie J. P. Native folding of an acetylcholine receptor alpha subunit expressed in the absence of other receptor subunits. J Biol Chem. 1988 Jan 15;263(2):1072–1080. [PubMed] [Google Scholar]
  2. Cachelin A. B., Jaggi R. Beta subunits determine the time course of desensitization in rat alpha 3 neuronal nicotinic acetylcholine receptors. Pflugers Arch. 1991 Dec;419(6):579–582. doi: 10.1007/BF00370298. [DOI] [PubMed] [Google Scholar]
  3. Cockcroft V. B., Osguthorpe D. J., Barnard E. A., Lunt G. G. Modeling of agonist binding to the ligand-gated ion channel superfamily of receptors. Proteins. 1990;8(4):386–397. doi: 10.1002/prot.340080412. [DOI] [PubMed] [Google Scholar]
  4. Couturier S., Erkman L., Valera S., Rungger D., Bertrand S., Boulter J., Ballivet M., Bertrand D. Alpha 5, alpha 3, and non-alpha 3. Three clustered avian genes encoding neuronal nicotinic acetylcholine receptor-related subunits. J Biol Chem. 1990 Oct 15;265(29):17560–17567. [PubMed] [Google Scholar]
  5. Deneris E. S., Connolly J., Rogers S. W., Duvoisin R. Pharmacological and functional diversity of neuronal nicotinic acetylcholine receptors. Trends Pharmacol Sci. 1991 Jan;12(1):34–40. doi: 10.1016/0165-6147(91)90486-c. [DOI] [PubMed] [Google Scholar]
  6. Figl A., Cohen B. N., Quick M. W., Davidson N., Lester H. A. Regions of beta 4.beta 2 subunit chimeras that contribute to the agonist selectivity of neuronal nicotinic receptors. FEBS Lett. 1992 Aug 24;308(3):245–248. doi: 10.1016/0014-5793(92)81284-s. [DOI] [PubMed] [Google Scholar]
  7. Guastella J., Nelson N., Nelson H., Czyzyk L., Keynan S., Miedel M. C., Davidson N., Lester H. A., Kanner B. I. Cloning and expression of a rat brain GABA transporter. Science. 1990 Sep 14;249(4974):1303–1306. doi: 10.1126/science.1975955. [DOI] [PubMed] [Google Scholar]
  8. Karlin A. Structure of nicotinic acetylcholine receptors. Curr Opin Neurobiol. 1993 Jun;3(3):299–309. doi: 10.1016/0959-4388(93)90121-e. [DOI] [PubMed] [Google Scholar]
  9. Koshland D. E., Jr, Némethy G., Filmer D. Comparison of experimental binding data and theoretical models in proteins containing subunits. Biochemistry. 1966 Jan;5(1):365–385. doi: 10.1021/bi00865a047. [DOI] [PubMed] [Google Scholar]
  10. Luetje C. W., Patrick J. Both alpha- and beta-subunits contribute to the agonist sensitivity of neuronal nicotinic acetylcholine receptors. J Neurosci. 1991 Mar;11(3):837–845. doi: 10.1523/JNEUROSCI.11-03-00837.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Luetje C. W., Piattoni M., Patrick J. Mapping of ligand binding sites of neuronal nicotinic acetylcholine receptors using chimeric alpha subunits. Mol Pharmacol. 1993 Sep;44(3):657–666. [PubMed] [Google Scholar]
  12. Maconochie D. J., Knight D. E. A study of the bovine adrenal chromaffin nicotinic receptor using patch clamp and concentration-jump techniques. J Physiol. 1992 Aug;454:129–153. doi: 10.1113/jphysiol.1992.sp019257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Papke R. L., Duvoisin R. M., Heinemann S. F. The amino terminal half of the nicotinic beta-subunit extracellular domain regulates the kinetics of inhibition by neuronal bungarotoxin. Proc Biol Sci. 1993 May 22;252(1334):141–148. doi: 10.1098/rspb.1993.0058. [DOI] [PubMed] [Google Scholar]
  14. Papke R. L., Heinemann S. F. The role of the beta 4-subunit in determining the kinetic properties of rat neuronal nicotinic acetylcholine alpha 3-receptors. J Physiol. 1991;440:95–112. doi: 10.1113/jphysiol.1991.sp018698. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Papke R. L. The kinetic properties of neuronal nicotinic receptors: genetic basis of functional diversity. Prog Neurobiol. 1993 Oct;41(4):509–531. doi: 10.1016/0301-0082(93)90028-q. [DOI] [PubMed] [Google Scholar]
  16. Pedersen S. E., Cohen J. B. d-Tubocurarine binding sites are located at alpha-gamma and alpha-delta subunit interfaces of the nicotinic acetylcholine receptor. Proc Natl Acad Sci U S A. 1990 Apr;87(7):2785–2789. doi: 10.1073/pnas.87.7.2785. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Sine S. M. Molecular dissection of subunit interfaces in the acetylcholine receptor: identification of residues that determine curare selectivity. Proc Natl Acad Sci U S A. 1993 Oct 15;90(20):9436–9440. doi: 10.1073/pnas.90.20.9436. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Unwin N. Neurotransmitter action: opening of ligand-gated ion channels. Cell. 1993 Jan;72 (Suppl):31–41. doi: 10.1016/s0092-8674(05)80026-1. [DOI] [PubMed] [Google Scholar]
  19. Vernino S., Amador M., Luetje C. W., Patrick J., Dani J. A. Calcium modulation and high calcium permeability of neuronal nicotinic acetylcholine receptors. Neuron. 1992 Jan;8(1):127–134. doi: 10.1016/0896-6273(92)90114-s. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of General Physiology are provided here courtesy of The Rockefeller University Press

RESOURCES