Abstract
Four critically positioned amino acids on each of the αβ, δ and γ sunits of the Torpedo nicotinic acetylcholine receptor are determinants of channel conductance. Our results show that the γ and ε{lunate} subunits of Xenopus muscle receptors are identical at all four positions, despite the fact that α2βδε{lunate} receptors have a 50% greater conductance than α2βδγ receptors. Instead, the functional difference is conferred by a single charged residue that lies extracellular to all four positions, corresponding to a location in the Torpedo receptor previously shown to have no influence on conductance. Substitution of a positively charged lysine residue in γ by the neutral methionine in ε{lunate} at this extracellular position is responsible for the increased conductance during maturation of the amphibian neuromuscular junction.
Original language | English (US) |
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Pages (from-to) | 865-870 |
Number of pages | 6 |
Journal | Neuron |
Volume | 14 |
Issue number | 4 |
DOIs | |
State | Published - Apr 1995 |
Externally published | Yes |
ASJC Scopus subject areas
- General Neuroscience