Potentiation of acetylcholine receptors by divalent cations.
Divalent cations promote activation of several nicotinic acetylcholine receptor (AChR) subtypes, presumably by lowering the energetic barrier between open and closed conformations. In wild-type alpha7 AChRs, binding of calcium to a particular part of the extracellular domain is required for potentiating activation. McLaughlin et al. (p. 16) tested the hypothesis that movements involved in agonist activation and calcium modulation involve a nearby beta sheet by linking strands within this sheet through disulfide bonds formed by replacing adjacent amino acids with cysteines to alter its mobility. These studies are helping to reveal how movements initiated by agonist binding to ACh binding sites are propagated through the extracellular domain of AChRs to regulate opening of the cation channel through the membrane.
Lindstrom
Jon
J
Department of Neuroscience, University of Pennsylvania Medical School, 217 Stemmler Hall, 36th and Hamilton Walk, Philadelphia, PA 19104-6074, USA. jslkk@mail.med.upenn.edu
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D008564:Membrane Potentials / Q000187:drug effects; D008958:Models, Molecular; D009154:Mutation; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D017433:Protein Structure, Secondary; D011978:Receptors, Nicotinic / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis; D064569:alpha7 Nicotinic Acetylcholine Receptor
D002413:Cations, Divalent; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor; D001464:Barium; D000109:Acetylcholine; D002118:Calcium