Received October 30, 2003
Revised December 17, 2003
Accepted after revision January 13, 2004
Mechanisms of channel gating of the ligand-gated ion channel superfamily inferred from protein structure
Nathan L Absalom 1,
Trevor M Lewis 2,
Peter R Schofield 1*
1 Garvan Institute of Medical Research
2 University of New South Wales
* To whom correspondence should be addressed. E-mail: p.schofield{at}garvan.org.au.
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Abstract |
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The nicotinic-like ligand-gated ion channel receptor superfamily consists of a group of structurally related receptors that activate an integral ion channel after the extracellular binding of ligands. The recent publications of the crystal structure of an acetylcholine binding protein and a refined electron micrograph structure of the membrane-bound segment of an acetylcholine receptor have led to new insights into the molecular determinants of receptor function. The structures have confirmed much biochemical and electrophysiological data obtained from the various ligand-gated ion channel receptors, and have also provided new opportunities to further study the mechanisms that allow ligand-binding stimulated channel activation. In particular, the structural models have provided new testable hypothesis concerning the domains and individual residues that are involved in the process of signal transduction and channel activation. Here we review the mechanisms of channel gating that have been elucidated by information gained from the structures of the acetylcholine binding protein and membrane-bound segment of the acetylcholine receptor and from the recent publications of experimental studies of receptor structure and function that have been based on the structural studies.
Key Words:
Ion channel, Receptor, Synaptic transmission
