P2X purinoceptor 2 (P2X2) (P2X2)

The P2X purinoceptor 2 (P2X2) is a ligand-gated ion channel that opens in response to the binding of extracellular adenosine triphosphate (ATP) (UniProt P55326). It is widely expressed throughout the central and peripheral nervous systems, where it facilitates rapid excitatory neurotransmission and modulates various physiological processes, including sensory perception and autonomic regulation (PubMed: 22303018). In the inner ear, P2X2 plays a critical role in maintaining hearing sensitivity and protecting against noise-induced damage; consequently, mutations in the P2RX2 gene are linked to autosomal dominant non-syndromic hearing loss (DFNA41) (NIH: GeneReviews). Beyond the auditory system, P2X2 is involved in pain signaling, respiratory control via the carotid body, and gastrointestinal motility (PubMed: 25633110). While several non-selective antagonists like suramin and PPADS are used in research to study P2X2 function, the development of highly selective therapeutic agents remains a challenge due to the structural similarity among P2X receptor subtypes (PubChem). Targeting P2X2 offers potential for treating chronic pain and sensory disorders, though safety considerations regarding its broad expression in the autonomic nervous system must be addressed.

Other names

P2RX2Purinergic receptor P2X 2ATP-gated ion channel P2X2Purinoceptor P2X2

The P2X2 receptor functions as a trimeric cation channel that, upon binding extracellular ATP, undergoes a conformational change to open a pore permeable to Na+, K+, and Ca2+, resulting in cell depolarization and activation of downstream signaling pathways (UniProt P55326).