Abstract
THE predominant inhibitory neurotrasmitter of the brain, GABA (γ-amino butyric acid), activates chloride-selective ion pores integral to the receptor complex. Subunits comprising the pre-sumed hetero-pentameric GABA channel have been cloned1–4, but little information is available on the domains important for activation. Rat wild-type or mutated α1-, & beta;2- and γ2-subunits (designated α, β and γ) were coexpressed in Xenopus oocytes and examined electrophy siologically. We report here the identification of two separate and homologous domains of the β-subunit, each of which contributes a tyrosine and threonine essential for activation by GABA. Conservative substitution of each of these four amino acids dramatically decreased GABA channel sensitivity to activation by GABA and the GABA agonist muscimol. These substitutions, however, did not impair activation by the barbiturate pentobarbital, indicating these two different classes of agonists activate GABA channels through distinct mechanisms. We also present evidence suggesting that the two identified domains of the β-subunit contribute a major component of the GABA receptor.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Schofield, P. R. et al. Nature 328, 221–227 (1987).
Khrestchatisky, M. et al. Neuron 3, 745–753 (1989).
Lolait, S. J. et al. FEBS Lett. 246, 145–148 (1989).
Shivers, B. D. et al. Neuron 3, 327–337 (1989).
Frieda, S., Pearce, A., Preston-HurlBurt, P. & Hawrot, E. Proc. R. Soc. B241, 207–213 (1990).
Galzi, J. L. et al. FEBS Lett. 294, 198–202 (1991).
O'Leary, M. E. & White, M. M. J. biol. Chem. 267, 8360–8365 (1992).
Dennis, M. et al. Biochemistry 27, 2346–2357 (1988).
Tomaselli, G. F., McLaughlin, J. T., Juman, M. E., Hawrot, E. & Yellen, G. Biophys. J. 60, 721–727 (1991).
Schmieden, V., Kuhse, J. & Betz, H. EMBO J. 11, 2025–2032 (1992).
Vandenberg, R. J., Handford, C. A. & Schofield, P. R. Neuron 9, 491–496 (1992).
Del Castillo, J. & Katz, B. Proc. R. Soc. B146, 369–381 (1957).
Weiss, D. S. & Magleby, K. L. J. Neurosci. 9, 1314–1324 (1989).
Twyman, R. E., Rogers, C. J. & Macdonald, R. L. J. Physiol., Lond. 423, 193–220 (1990).
Casalotti, S. O., Stephenson, A. & Barnard, E. J. biol. Chem. 261, 15013–15016 (1986).
Deng, L., Ransom, R. W. & Olsen, R. W. Biochem. biophys. Res. Commun. 138, 1308–1314 (1986).
Sigel, E., Baur, R., Trube, G., Mohler, H. & Malherbe, P. Neuron 5, 703–711 (1990).
Sigel, E., Baur, R., Kellenberger, S. & Malherbe, P. EMBO J. 11, 2017–2023 (1992).
Nicoll, R. A., Eccles, J. C., Oshima, T. & Rubia, F. Nature 258, 625–627 (1975).
Barker, J. L. & Ransom, B. R. J. Physiol., Lond. 280, 355–372 (1978).
Nicoll, R. A. & Wojtowicz, J. M. Brain Res. 191, 225–237 (1980).
Schulz, D. W. & MacDonald, R. L. Brain Res. 209, 177–188 (1981).
Branden, C. & Tooze, J. Introduction to Protein Structure (Garland, New York, 1991).
Galzi, J.-L., Revah, F., Bessis, A. & Changeux, J.-P. A. Rev. Pharmac. 31, 37–72 (1991).
Crawford, J. L., Lipscomb, W. N. & Schellman, C. G. Proc. natn. Acad. Sci. U.S.A. 70, 538–542 (1973).
Levitan, E. S., Blair, L. A. C., Dionne, V. E. & Barnard, E. A. Neuron 1, 773–781 (1988).
Verdoorn, T. A., Draguhn, A., Ymer, S., Seeburg, P. H. & Sakmann, B. Neuron 4, 919–928 (1990).
Pritchett, D. B. et al. Nature 338, 582–585 (1989).
Saiki, R. K. et al. Science 239, 487–491 (1988).
Colquhoun, D. & Hawkes, A. G. Proc. R. Soc. B211, 205–235 (1981).
Colquhoun, D. & Ogden, D. C. J. Physiol., Lond. 395, 131–159 (1988).
Colquhoun, D., Ogden, D. C. & Cachelin, A. B. Ion Channels in Neural Membranes (Plenum, New York, 1986).
Sakmann, B., Hamill, O. P. & Bormann, J. J. Neural Transm. 18(suppl.), 83–95 (1983).
Newland, C. F., Colquhoun, D. & Cull-Candy, S. G. J. Physiol., Lond. 432, 203–233 (1991).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Amin, J., Weiss, D. GABAA receptor needs two homologous domains of the & beta;-subunit for activation by GABA but not by pentobarbital. Nature 366, 565–569 (1993). https://doi.org/10.1038/366565a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/366565a0
This article is cited by
-
Neurosteroids and their potential as a safer class of general anesthetics
Journal of Anesthesia (2024)
-
Electrophysiology of ionotropic GABA receptors
Cellular and Molecular Life Sciences (2021)
-
Steady-state activation of the high-affinity isoform of the α4β2δ GABAA receptor
Scientific Reports (2019)
-
Cryo-EM structure of the human α1β3γ2 GABAA receptor in a lipid bilayer
Nature (2019)
-
Structure of a human synaptic GABAA receptor
Nature (2018)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.