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