Inward rectifier potassium channel 4 (Kir2.3) (Kir2.3)

The Inward rectifier potassium channel 4 (Kir2.3), encoded by the KCNJ4 gene, is a member of the inwardly rectifying potassium channel family that plays a vital role in stabilizing the resting membrane potential (UniProt: P48050). These channels preferentially allow potassium ions to flow into the cell, thereby controlling the excitability of neurons and cardiomyocytes (NCBI Gene: 3761). Kir2.3 is predominantly expressed in the central nervous system, specifically within the hippocampus and forebrain, where it often associates with PDZ-domain proteins to modulate synaptic transmission (PubMed: 10433262). In the heart, Kir2.3 contributes to the IK1 current, which is essential for the terminal repolarization phase of the action potential (PubMed: 11886830). Dysfunction of Kir2.3 has been linked to various pathological states, including cardiac arrhythmias and potential roles in neuropsychiatric conditions (PubMed: 25833132). While it is a recognized therapeutic target, the development of highly selective ligands remains a challenge in pharmacology, with current interactions limited to non-specific blockers like barium or multi-channel antiarrhythmics like flecainide (PubChem: CID 3356).

Other names

KCNJ4HIRHIRK2IRK3HRK1Potassium inwardly rectifying channel subfamily J member 4

Inhibition of potassium efflux through the channel pore to modulate membrane potential and action potential duration.