Alternate stoichiometries of alpha4beta2 nicotinic acetylcholine receptors.
Publication/Presentation Date
2-1-2003
Abstract
Two functional types of nicotinic acetylcholine receptors (nAChRs) are expressed when human embryonic kidney cells are permanently transfected with equal amounts of human alpha4 and beta2 subunit cDNAs. Most (82%) of these nAChRs exhibit an EC(50) of 74 +/- 6 microM for ACh, a much lower sensitivity than the remaining fraction (EC(50) of 0.7 +/- 0.4 microM) or than expected from expression of equal amounts of alpha4 and beta2 mRNAs in Xenopus laevis oocytes. We have found three conditions that can increase the number of nAChRs with high sensitivity to activation. These are: 1) transient transfection with additional beta2 subunits, 2) overnight incubation in nicotine, or 3) overnight culture at 29 degrees C. Using metabolic labeling with [(35)S]methionine to measure subunit stoichiometry, we found that the majority of nAChRs had a stoichiometry of (alpha4)(3)(beta2)(2). Overnight treatment with nicotine increased the number of nAChRs and increased the proportion of the (alpha4)(2)(beta2)(3) stoichiometry. Alternate alpha4beta2 nAChR stoichiometries with distinct functional properties raise the possibility for an interesting mode of synaptic regulation for nicotinic signaling in the mammalian brain.
Volume
63
Issue
2
First Page
332
Last Page
341
ISSN
0026-895X
Published In/Presented At
Nelson, M. E., Kuryatov, A., Choi, C. H., Zhou, Y., & Lindstrom, J. (2003). Alternate stoichiometries of alpha4beta2 nicotinic acetylcholine receptors. Molecular pharmacology, 63(2), 332–341. https://doi.org/10.1124/mol.63.2.332
Disciplines
Medicine and Health Sciences
PubMedID
12527804
Department(s)
Fellows and Residents
Document Type
Article