P2RX3

P2RX3 or P2X purinoceptor 3 is a protein that in humans is encoded by the P2RX3 gene. It is a member of the P2X receptor family, a group of ATP-gated ion channels that play a role in various physiological processes, including inflammation, pain perception, and taste transduction.

Structure

The P2RX3 protein is a trimeric ion channel that is permeable to cations, including sodium, calcium, and potassium ions. Each subunit of the trimer consists of two transmembrane domains, a large extracellular loop, and intracellular N- and C-termini. The extracellular loop contains ten conserved cysteine residues, which are thought to be involved in receptor activation and desensitization.

Function

P2RX3 receptors are primarily expressed in sensory neurons, where they play a key role in the transmission of pain signals. Activation of these receptors by ATP leads to the opening of the ion channel, allowing the influx of cations and resulting in depolarization of the neuron. This depolarization can trigger the release of neurotransmitters, such as substance P and calcitonin gene-related peptide (CGRP), which are involved in the transmission of pain signals to the central nervous system.

Clinical significance

Mutations in the P2RX3 gene have been associated with various pain disorders, including chronic pain and neuropathic pain. In addition, upregulation of P2RX3 expression has been observed in conditions such as irritable bowel syndrome and bladder pain syndrome. As such, P2RX3 is considered a potential therapeutic target for the treatment of these and other pain-related conditions.

See also

• P2X receptor
• Pain perception
• Irritable bowel syndrome
• Bladder pain syndrome