Kir4.2 channels

Channel name Kir4.2
Description Inwardly rectifying potassium channel Kir4.2 subunit
Other names Kir1.3, IRKK
Molecular information Human (KCNJ15): 375aa, Locus ID: 3772, GenBank: Y10745, NM_002243, PMID: 8995301,1 chr. 21q22.2
Rat (Kcnj15): 375 or 405aa, Locus ID: 170847, GenBank: AY028455, NM_133321, PMID: 11804844,2 chr. 11q11
Mouse (Kcnj15): 375aa, Locus ID: 16516, GenBank: AF085696, NM_019664, PMID: 9882736,3 chr. 16, 69.1 centimorgans
Associated subunits Reported to interact with Kir1.1 (inhibits) and Kir5.1 (forms novel channels) when coexpressed in heterologous expression systems
Functional assays Voltage-clamp
Current Inwardly rectifying K+ current
Conductance 25.2pS (120 mM K+)4
Ion selectivity K+
Activation Not established
Inactivation Intracellular acidification
Activators None
Gating inhibitors None
Blockers Nonselective: Ba2+, Cs+
Radioligands None
Channel distribution Kidney (cortex), pancreas, liver (hepatocyte basolateral membrane), lung, testes
Physiological functions Not established
Mutations and pathophysiology Not established
Pharmacological significance Not established
Comments Two splice variants have been identified in rat: Kir4.2 (375aa) and Kir4.2a (405aa)
  • aa, amino acids; chr., chromosome.

  • 1. Shuck ME, Piser TM, Bock JH, Slightom JL, Lee KS, and Bienkowski MJ (1997) Cloning and characterization of two K+ inward rectifier (Kir) 11 potassium channel homologs from human kidney (Kir1.2 and Kir1.3). J Biol Chem 272:586-593

  • 2. Hill CE, Briggs MM, Liu J, and Magtanong L (2002) Cloning expression and localization of a rat hepatocyte inwardly rectifying potassium channel. Am J Physiol Gastrointest Liver Physiol 282:G233-G240

  • 3. Pearson WL, Dourrado M, Schreiber M, Salkoff, L, and Nichols CG (1999) Expression of a functional Kir4 family inward rectifier K+ channel from a gene cloned from mouse liver. J Physiol 514:639-653

  • 4. Pessia M, Imbrici P, D'Adamo MC, Salvatore L, and Tucker SJ (2001) Differential pH sensitivity of Kir4.1 and Kir4.2 potassium channels and their modulation by heteropolymerisation with Kir5.1. J Physiol 532:359-367