Characterization of an adult muscle acetylcholine receptor subunit by expression in fibroblasts

Paul Blount, John Paul Merlie

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

To study the functional and structural roles of the ε subunit in adult muscle acetylcholine receptor (AChR), we have co-expressed the α and ε subunits of the mouse receptor in transfected fibroblasts. Ligand binding studies suggest that association of ε with α subunit results in a lower association rate constant for 125I-labeled α-bungarotoxin binding than that of the unassembled α subunit, approaching that for toxin binding to the AChR. Furthermore, αε complexes contain high affinity binding sites for competitive antagonists and agonists not present in the unassembled α subunit, but similar to one of the two nonequivalent binding sites in the adult AChR. Structural analysis of αε complexes by sucrose gradient velocity centrifugation suggests that some of the complexes formed are trimers or tetramers of α and ε subunits. Comparison of these data with those previously obtained for αε complexes suggests that γ and ε have homologous functional roles and identical structural positions in the fetal and adult AChRs, respectively.

Original languageEnglish (US)
Pages (from-to)14692-14696
Number of pages5
JournalJournal of Biological Chemistry
Volume266
Issue number22
StatePublished - 1991

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Cholinergic Receptors
Fibroblasts
Muscle
Muscles
Binding Sites
Association reactions
Bungarotoxins
Centrifugation
Structural analysis
Sucrose
Rate constants
Ligands

ASJC Scopus subject areas

  • Biochemistry

Cite this

Characterization of an adult muscle acetylcholine receptor subunit by expression in fibroblasts. / Blount, Paul; Merlie, John Paul.

In: Journal of Biological Chemistry, Vol. 266, No. 22, 1991, p. 14692-14696.

Research output: Contribution to journalArticle

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