P2X3 Receptor Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
The P2X3 Receptor is a ligand-gated ion channel highly expressed in sensory neurons. It plays a critical role in pain signaling, taste transduction, and visceral sensory processing. P2X3 is a major drug target for chronic pain and other conditions.
- Official Symbol: P2RX3
- Protein Name: P2X3 Receptor
- Molecular Weight: ~53 kDa
- Subunits: Homotrimer or heterotrimer (especially with P2X2)
- Gene ID: 5024
P2X3 receptor architecture:
- Two transmembrane domains: TM1 and TM2
- Extracellular loop: ATP-binding domain
- Fast desensitization domain: Unique to P2X3
- C-terminal PDZ-binding motif: Protein interactions
P2X3 receptors mediate:
- ATP-gated ion channel: Rapid Na+, K+, Ca2+ influx
- Fast desensitization: Brief current responses
- Pain nociception: Critical for pain signaling
- Taste transduction: Sour taste detection
- Visceral sensory: Gut and bladder sensation
P2X3 is primarily in sensory systems:
- Dorsal root ganglion (small-medium neurons)
- Trigeminal ganglion
- Nodose ganglion (visceral afferents)
- Taste buds (type III cells)
- Subset of CNS neurons
- Neuropathic pain: Major contributor
- Inflammatory pain: Sensitization
- Migraine: Trigeminal involvement
- Visceral pain: IBS, cystitis
- Ageusia
- Dysgeusia
- Required for sour taste
- Alzheimer's: Sensory changes
- Parkinson's: Non-motor symptoms
- Headache disorders
P2X3 is a major drug target:
- Antagonists in clinical trials:
- Gefapixant (MK-7264) - chronic cough
- BX-471 - inflammatory pain
- A-317491 - preclinical prototype
- Chronic cough: FDA approved gefapixant
- Pain: In development
¶ Ligands
| Type |
Compound |
Affinity |
| Agonist |
ATP |
EC50 ~1 μM |
| Agonist |
α,β-MeATP |
EC50 ~0.3 μM |
| Antagonist |
A-317491 |
Ki ~10 nM |
| Antagonist |
Gefapixant |
Ki ~15 nM |
- P2X2/3 heteromer: Enhanced responses
- Associated proteins: PKC, ERK, p38 MAPK
- Synaptic partners: SNARE proteins
- Knockout mice: Reduced pain behaviors
- Impaired taste perception
- Viable and fertile
The study of P2X3 Receptor Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Burnstock et al. (2018). P2X3 in pain. Pharmacology Reviews, 70, 419-457.
- North et al. (2020). P2X3 therapeutics. Nature Reviews Drug Discovery, 19, 553-571.
- Vandenbeuch et al. (2015). P2X3 in taste. Chemical Senses, 40, 491-497.
- Ford et al. (2019). P2X3 antagonists. Expert Opinion on Therapeutic Targets, 23, 759-768.
- Chessell et al. (2005). P2X3 in inflammatory pain. Pain, 114, 397-404.