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P2X receptors C

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


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P2X receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on P2X Receptors [7,32]) have a trimeric topology [28,31,46] with two putative TM domains, gating primarily Na+, K+ and Ca2+, exceptionally Cl-. The Nomenclature Subcommittee has recommended that for P2X receptors, structural criteria should be the initial criteria for nomenclature where possible. X-ray crystallography indicates that functional P2X receptors are trimeric and three agonist molecules are required to bind to a single receptor in order to activate it [19-20,31,38]. Native receptors may occur as either homotrimers (e.g. P2X1 in smooth muscle) or heterotrimers (e.g. P2X2:P2X3 in the nodose ganglion [59], P2X1:P2X5 in mouse cortical astrocytes [36], and P2X2:P2X5 in mouse dorsal root ganglion, spinal cord and mid pons [8,52]. P2X2, P2X4 and P2X7 receptor activation can also lead to influx of large cationic molecules, such as NMDG, Yo-Pro, ethidium or propidium iodide [51]. The hemi-channel pannexin-1 was initially implicated in the action of P2X7 [50], but not P2X2, receptors [6], but this interpretation is probably misleading. Convincing evidence now supports the view that the activated P2X7 receptor is immediately permeable to large cationic molecules, but influx proceeds at a much slower pace than that of the small cations Na+, K+, and Ca2+ [11].

Channels and Subunits

P2X1 C Show summary » More detailed page

P2X2 C Show summary » More detailed page

P2X3 C Show summary » More detailed page

P2X4 C Show summary » More detailed page

P2X5 C Show summary » More detailed page

P2X6 C Show summary » More detailed page

P2X7 C Show summary » More detailed page


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Further reading

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NC-IUPHAR subcommittee and family contributors

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How to cite this family page

Database page citation (select format):

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Mathie A, Peters JA, Veale EL, Striessnig J, Kelly E, Armstrong JF, Faccenda E, Harding SD, Pawson AJ, Sharman JL, Southan C, Davies JA; CGTP Collaborators. (2019) The Concise Guide to PHARMACOLOGY 2019/20: Ion channels. Br J Pharmacol. 176 Issue S1: S142-228.