Kir2.4 channels

Channel name Kir2.4
Description Inwardly rectifying potassium channel Kir2.4 subunit
Other names IRK4
Molecular information Human (KCNJ14): 434aa, Locus ID: 3770, GenBank: AF181988, AF081466, NM_013348, NM_170720, PMID: 10723734,1 chr. 19q13.1-13.3
Rat (Kcnj14): 434aa, Locus ID 276720, AJ003065, NM_170718, PMID: 9592090,2 chr. 1q22
Mouse (Kcnj14): 434aa, Locus ID 211480, GenBank: NM_145963, PMID: 10942728,3 12477932,4 chr. 7
Associated subunits Can form heteromers with Kir2.1
Functional assays Voltage-clamp, Western blot
Current Not established
Conductance 15pS (in 140 mM K+)
Ion selectivity K+
Activation Not established
Inactivation Not established
Activators Extracellular alkalization
Gating inhibitors Extracellular Na+ ions, extracellular acidification (pKa = 7.14 human)
Blockers Nonselective: Ba2+ (IC50 = 72–116 μM at –120 mV3,5), Cs+ (IC50 = 40 μM3)
Radioligands None
Channel distribution Neuronal cells in heart, brain (restricted to cholinergic neurons in striatum and cranial motor nerve nuclei), retina
Physiological functions Setting the membrane potential near EK
Mutations and pathophysiology Not established
Pharmacological significance Not established
  • aa, amino acids; chr., chromosome.

  • 1. Töpert C, Döring F, Derst C, Daut J, Grzeschik KH, and Karschin A (2000) Cloning structure and assignment to chromosome 19q13 of the human Kir2.4 inwardly rectifying potassium channel gene (KCNJ14). Mamm Genome 11:247-249

  • 2. Töpert C, Doring F, Wischmeyer E, Karschin C, Brockhaus J, Ballanyi K, Derst C, and Karschin A (1998) Kir2.4: a novel brain K+ inward rectifier predominantly expressed in motoneurons of cranial nerve nuclei. J Neurosci 18:4096-4105

  • 3. Schram G, Melnyk P, Pourrier M, Wang Z, and Nattel S (2002) Kir2.4 and Kir2.1 K+ channel subunits co-assemble: a potential new contributor to inward rectifier current heterogeneity. J Physiol 544:337-349

  • 4. Strausberg RL, Feingold EA, Grouse H, Derge JG, Klausner RD, Collins FS, Shenmen CM, Schuler GD, Altshul SF, Zeeberg B, et al. (2002) Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences: Mammalian Gene Collection Program Team. Proc Natl Acad Sci USA 99:16899-16903

  • 5. Hughes BA, Kumar G, Yuan Y, Swaminathan A, Yan D, Sharma A, Plumley L, Yang-Feng T, and Swaroop A (2000) Cloning and functional expression of human retinal Kir2.4, a pH-sensitive inwardly rectifying K+ channel. Am J Physiol 279:C771-C784