Functional Properties of Native and Cloned P2X Receptors

  1. Derek J. Chadwick Organizer and
  2. Jamie A. Goode
  1. Annmarie Surprenant

Published Online: 28 SEP 2007

DOI: 10.1002/9780470514900.ch12

Ciba Foundation Symposium 198 - P2 Purinoceptors: Localization, Function and Transduction Mechanisms

Ciba Foundation Symposium 198 - P2 Purinoceptors: Localization, Function and Transduction Mechanisms

How to Cite

Surprenant, A. (2007) Functional Properties of Native and Cloned P2X Receptors, in Ciba Foundation Symposium 198 - P2 Purinoceptors: Localization, Function and Transduction Mechanisms (eds D. J. Chadwick and J. A. Goode), John Wiley & Sons, Ltd., Chichester, UK. doi: 10.1002/9780470514900.ch12

Author Information

  1. Glaxo Institute for Molecular Biology, 14 Chemin des Aulx, 1228 Plan-les-Ouates, CH-1211 Geneva, Switzerland

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471961253

Online ISBN: 9780470514900

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Keywords:

  • native P2X receptors;
  • cloned P2X receptors;
  • homo-oligomeric channels;
  • ATP-gated currents;
  • desensitizing responses

Summary

Electrophysiological experiments on dissociated smooth muscle and neurons have revealed three distinct phenotypes of P2X receptor: (1) a rapidly desensitizing, α,β-methylene ATP-sensitive response typical of most smooth muscle; (2) a non-desensitizing, α,β-methylene ATP-insensitive response characteristic of PC12 phaeochromocytoma cells and rat superior cervical ganglion neurons; and (3) a non-desensitizing, α,β-methylene ATP-sensitive response observed in sensory neurons. All of these purinoceptors share a similar cationic and high Ca2+ permeability and sensitivity to blockade by suramin, Cibacron blue, oxidized ATP, pyridoxal-5-phosphate and pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid. Heterologous expression of two forms of cloned P2X receptors (from rat vas deferens and PC12 cells) reveals that each cloned receptor can reconstitute native responses with remarkable fidelity. Such results suggest that homo-oligomeric channels may be formed from single subunits of the P2X receptor in smooth muscle, PC12 cells and some neurons. The third phenotype observed in native cells might result from co-assembly of subunits of the cloned receptors. However, co-expression studies show that these two forms of the P2X receptor do not heteropolymerize. Therefore, the non-desensitizing, α,β-methylene ATP-sensitive response observed in sensory neurons may result from a distinct P2X receptor or from heteropolymerization of more than one distinct P2X purinoceptor.