Purine and purinergic receptors

Brain Neurosci Adv. 2018 Dec 6:2:2398212818817494. doi: 10.1177/2398212818817494. eCollection 2018 Jan-Dec.


Adenosine 5'-triphosphate acts as an extracellular signalling molecule (purinergic signalling), as well as an intracellular energy source. Adenosine 5'-triphosphate receptors have been cloned and characterised. P1 receptors are selective for adenosine, a breakdown product of adenosine 5'-triphosphate after degradation by ectonucleotidases. Four subtypes are recognised, A1, A2A, A2B and A3 receptors. P2 receptors are activated by purine and by pyrimidine nucleotides. P2X receptors are ligand-gated ion channel receptors (seven subunits (P2X1-7)), which form trimers as both homomultimers and heteromultimers. P2Y receptors are G protein-coupled receptors (eight subtypes (P2Y1/2/4/6/11/12/13/14)). There is both purinergic short-term signalling and long-term (trophic) signalling. The cloning of P2X-like receptors in primitive invertebrates suggests that adenosine 5'-triphosphate is an early evolutionary extracellular signalling molecule. Selective purinoceptor agonists and antagonists with therapeutic potential have been developed for a wide range of diseases, including thrombosis and stroke, dry eye, atherosclerosis, kidney failure, osteoporosis, bladder incontinence, colitis, neurodegenerative diseases and cancer.

Keywords: Adenosine 5′-triphosphate; P1 receptor; P2X receptor; P2Y receptor; adenosine.

Publication types

  • Review