Transduction Mechanisms of P2Z Purinoceptors

  1. Derek J. Chadwick Organizer and
  2. Jamie A. Goode
  1. J. S. Wiley,
  2. J. R. Chen,
  3. M. S. Snook,
  4. C. E. Gargett and
  5. G. P. Jamieson

Published Online: 28 SEP 2007

DOI: 10.1002/9780470514900.ch9

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

Wiley, J. S., Chen, J. R., Snook, M. S., Gargett, C. E. and Jamieson, G. P. (2007) Transduction Mechanisms of P2Z Purinoceptors, 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.ch9

Author Information

  1. Haematology Department, Austin Hospital, Studley Road, Heidelberg, Victoria 3084, Australia

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471961253

Online ISBN: 9780470514900

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Keywords:

  • transduction mechanisms;
  • P2Z purinoceptors;
  • Na+ concentrations;
  • L-selectin;
  • extracellular ATP

Summary

The ability of extracellular ATP to increase the cation permeability of a variety of fresh and cultured cells has been known for decades, but evidence of a separate class of P2 purinoceptor, termed P2Z, which mediates this effect has only recently been obtained. Several features of the P2Z purinoceptor clearly distinguish it from other P2 purinoceptors and show that it is a ligand-gated ion channel. P2Z purinoceptors are highly selective for the ATP4− species and addition of Mg2+ in excess over ATP closes the channel. The most potent agonist is 3′-O-(4-benzoyl)benzoyl ATP which has a 10-fold lower EC50 than ATP. Ca2+ is the preferred permeant for the P2Z ion channel although it will pass ions up to the size of ethidium+ (314Da) in lymphocytes or fura-2 (813 Da) in macrophages. The inhibitors of the P2Z purinoceptor or its associated ion channel include suramin, amiloride analogues, high extracellular Na+ concentrations and 2′,3′-dialdehyde ATP (oxidized ATP), which blocks irreversibly. Occupancy of P2Z purinoceptors stimulates a phospholipase D activity, which may be involved in membrane remodelling. Moreover, extracellular ATP causes loss of the glycosylated adhesion molecule L-selectin from the surface of human lymphocytes by enzymic cleavage, suggesting a possible role for P2Z purinoceptors in intercellular interactions.