P2X46

P2X46 is a designation used in some genomic and proteomic annotations to refer to a putative member of the P2X receptor family, a class of ATP-gated cation channels. The best-characterized P2X receptors are the trimeric channels formed by subunits P2X1 through P2X7, and P2X46 is not universally recognized as a distinct, well-characterized human gene. In certain databases, P2X46 may reflect a predicted gene model, a splice variant, or a species-specific paralog that has not been functionally validated.

Structure and mechanism are inferred from the broader P2X receptor family. If P2X46 corresponds to a functional subunit, it would be expected to contribute to the formation of a trimeric, ATP-activated channel with two transmembrane domains per subunit and a large extracellular ATP-binding domain. Activation by extracellular ATP would typically permit the flow of cations such as Na+, K+, and Ca2+, producing depolarization and various downstream signaling effects.

Expression patterns for P2X46, where established, appear to be tissue- or species-specific and are not consistently described across studies. Pharmacological characterization remains limited; while ATP is the canonical agonist for P2X receptors, the availability of selective ligands for a putative P2X46 subunit is unclear.

Overall, P2X46 remains poorly characterized. Further experimental evidence is required to confirm its existence as a distinct functional subunit, determine its tissue distribution, and define its physiological and pharmacological roles. See also P2X receptor family and P2X1–P2X7.