A single site on the ϵ subunit is responsible for the change in ACh receptor channel conductance during skeletal muscle development

Nancy Murray, Ying Cong Zheng, Gail Mandel, Paul Brehm, Reese Bolinger, Quentin Reuer, Richard Kullberg

Research output: Contribution to journalArticle

20 Scopus citations


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 languageEnglish (US)
Pages (from-to)865-870
Number of pages6
Issue number4
StatePublished - Apr 1995


ASJC Scopus subject areas

  • Neuroscience(all)

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