Mutations in the channel domain of a neuronal nicotinic receptor convert ion selectivity from cationic to anionic

• DOI: 10.1038/359500a0
• Publication Date: 2003-06-12T23:34:24Z
• Authors: Jean-Luc Galzi; Anne Devillers-Th...; Nicolas Hussy; Sonia Bertrand; Jean-Pierre Changeux; Daniel Bertrand
• Keywords: Anions; Neurons; 0303 health sciences; Sequence Homology, Amino Acid; Molecular Sequence Data; Receptors, Nicotinic; Receptors, GABA-A; Acetylcholine; Ion Channels; Permeability; Receptors, Neurotransmitter; 03 medical and health sciences; Receptors, Glycine; Cations; Mutagenesis, Site-Directed; Oocytes; Animals; Calcium; Amino Acid Sequence; Egtazic Acid; Ion Channel Gating; Chelating Agents

Introduction by site-directed mutagenesis of three amino acids from the MII segment of glycine or gamma-aminobutyric acid (GABAA) receptors into the MII segment of alpha 7 nicotinic receptor was sufficient to convert a cation-selective channel into an anion-selective channel gated by acetylcholine. A critical mutation was the insertion of an uncharged residue at the amino-terminal end of MII, stressing the importance of protein geometrical constraints on ion selectivity.