Structural and Functional Heterogeneity of Nicotinic Receptors

  1. Greg Bock Organizer and
  2. Joan Marsh
  1. Jon Lindstrom,
  2. Ralf Schoepfer,
  3. William G. Conroy and
  4. Paul Whiting

Published Online: 28 SEP 2007

DOI: 10.1002/9780470513965.ch3

Ciba Foundation Symposium 152 - The Biology of Nicotine Dependence

Ciba Foundation Symposium 152 - The Biology of Nicotine Dependence

How to Cite

Lindstrom, J., Schoepfer, R., Conroy, W. G. and Whiting, P. (2007) Structural and Functional Heterogeneity of Nicotinic Receptors, in Ciba Foundation Symposium 152 - The Biology of Nicotine Dependence (eds G. Bock and J. Marsh), John Wiley & Sons, Ltd., Chichester, UK. doi: 10.1002/9780470513965.ch3

Author Information

  1. Receptor Biology Laboratory, The Salk Institute for Biological Studies, PO Box 85800, San Diego, California 92138-9216, USA

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471926887

Online ISBN: 9780470513965

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Keywords:

  • heterogeneity;
  • nicotinic receptors;
  • nicotinic acetylcholine receptors;
  • bind cholinergic ligands;
  • cDNA

Summary

Three gene families of the ligand-gated ion channel gene superfamily encode proteins which bind cholinergic ligands: (1) nicotinic acetylcholine receptors (AChRs) from skeletal muscle, (2) AChRs from neurons, and (3) neuronal α-bungarotoxin-binding proteins (αBgtBPs). AChRs from muscles and nerves function as ACh-gated cation channels, but αBgtBPs do not appear to function in this way. A family of neuronal AChR subtypes has been characterized using monoclonal antibodies and cDNA probes. Neuronal AChRs exhibit sequence homologies with muscle AChRs, but differ in subunit composition, pharmacological and electrophysiological properties, and, in some cases, apparent functional roles. The genes that encode the subunits of the various purified AChR subtypes have been determined in several cases. Histological localization of AChR subunit mRNAs by in situ hybridization and of subunit proteins by immunohistochemistry is being conducted with increasing resolution. The subunit structure of αBgtBP is uncertain, but cDNAs have been identified for two subunits. Sequences of these cDNAs reveal that αBgtBPs are members of the ligand-gated ion channel gene family, and suggest that they could function as gated cation channels. Biochemical and molecular genetic approaches to studies of neuronal AChRs and related proteins are merging to provide a detailed description of a complex family of AChRs widely dispersed throughout the nervous system, which are probably important to many activities of the nervous system, but whose functional roles are not yet well characterized.