P2X2 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 P2X2 Receptor is a ligand-gated ion channel activated by extracellular ATP. It is widely expressed in the nervous system, particularly in the inner ear, and plays essential roles in hearing, synaptic transmission, and autonomic functions.
- Official Symbol: P2RX2
- Protein Name: P2X2 Receptor
- Molecular Weight: ~55 kDa
- Subunits: Homotrimer or heterotrimer (with P2X3, P2X5, P2X6)
- Gene ID: 5023
P2X2 receptor structure includes:
- Two transmembrane helices: TM1 and TM2
- Large extracellular domain: ATP-binding pocket
- Cysteine-rich loops: Conserved in P2X family
- C-terminal domain: Moderately long, involved in trafficking
P2X2 receptors mediate:
- ATP-gated cation channel: Na+, K+, Ca2+ permeation
- Slow desensitization: Sustained current responses
- Synaptic transmission: Purinergic signaling in CNS
- Auditory function: Cochlear hair cell signaling
- Heteromeric assembly: Forms functional heterotrimers
P2X2 is expressed in:
- Inner ear (cochlea, vestibular organs)
- Dorsal root ganglion
- Trigeminal ganglion
- Hippocampus and cortex
- Autonomic ganglia
- Neurosecretory cells
- DFNA41: Autosomal dominant hearing loss
- Auditory neuropathy: P2RX2 mutations
- Cochlear dysfunction: Essential for hearing
- Epilepsy: Altered purinergic signaling
- Neuropathic pain: Sensory transmission
- Cognitive function: Synaptic plasticity
- Bladder dysfunction
- Gastrointestinal motility
P2X2 receptors are therapeutic targets:
- Agonists: α,β-MeATP (P2X2/3 selective)
- Antagonists: Suramin, PPADS, KN-62
- Hearing restoration: Gene therapy approaches
¶ Ligands
| Type |
Compound |
Affinity |
| Agonist |
ATP |
EC50 ~10 μM |
| Agonist |
α,β-MeATP |
EC50 ~1 μM |
| Antagonist |
Suramin |
Ki ~1 μM |
| Antagonist |
PPADS |
Ki ~0.5 μM |
- P2X2/3 heteromer: P2X3 co-assembly
- P2X2/5 heteromer: Functional in some tissues
- Associated proteins: RACK1, Na+/K+-ATPase
- Knockout mice: Deaf with ABR abnormalities
- Transgenic models for hearing studies
- Useful for inner ear research
The study of P2X2 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.
- Housley et al. (2019). P2X receptors in the ear. Hearing Research, 378, 50-58.
- Jovanovic et al. (2020). P2X2 in auditory function. Purinergic Signalling, 16, 3-14.
- Jarvis et al. (2021). P2X receptors in the CNS. Neuropharmacology, 198, 108756.
- Rong et al. (2018). P2X receptors in neurodegeneration. Frontiers in Neuroscience, 12, 825.
- Muller et al. (2020). Purinergic signaling in the brain. Nature Reviews Neuroscience, 21, 263-275.