kir2.1 kir2.1 the kir2.1 inward-rectifier potassium channel is a lipid-gated ion channel encoded by the kcnj2 gene. kcnj2identifiersaliaseskcnj2, atfb9, hhbirk1, hhirk1, irk1, kir2.1, lqt7, sqt3, potassium voltage-gated channel subfamily j member 2, potassium inwardly rectifying channel subfamily j member 2external idsomim: 600681 mgi: 104744 homologene: 20249 genecards: kcnj2 gene location (human)chr.chromosome 17 (human)band17q24.3start70,168,673 bpend70,180,044 bpgene location (mouse)chr.chromosome 11 (mouse)band11 e2|11 75.23 cmstart110,956,990 bpend110,967,647 bprna expression patternbgeehumanmouse (ortholog)top expressed ininferior ganglion of vagus nerveponssubthalamic nucleuscorpus callosumsuperior vestibular nucleusinferior olivary nucleusbody of tonguevastus lateralis muscledeltoid muscleventral tegmental areatop expressed insuperior frontal gyrusliptemporal muscleesophagusupper armdermal bonemaxillamandibleinterventricular septumskeletal muscle tissuemore reference expression databiogpsmore reference expression datagene ontologymolecular function voltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization voltage-gated ion channel activity identical protein binding phosphatidylinositol-4,5-bisphosphate binding inward rectifier potassium channel activity g-protein activated inward rectifier potassium channel activity cellular component integral component of membrane rough endoplasmic reticulum golgi apparatus membrane intercalated disc t-tubule voltage-gated potassium channel complex plasma membrane dendritic spine integral component of plasma membrane smooth endoplasmic reticulum neuronal cell body dendrite intrinsic component of membrane biological process cardiac muscle cell action potential regulation of ion transmembrane transport magnesium ion transport cardiac muscle cell action potential involved in contraction ion transport cellular potassium ion homeostasis potassium ion transport regulation of cardiac muscle cell contraction cellular response to mechanical stimulus membrane repolarization during action potential potassium ion transmembrane transport positive regulation of potassium ion transmembrane transport regulation of skeletal muscle contraction via regulation of action potential regulation of resting membrane potential regulation of membrane repolarization relaxation of skeletal muscle regulation of heart rate by cardiac conduction membrane repolarization during cardiac muscle cell action potential protein homotetramerization relaxation of cardiac muscle membrane depolarization during cardiac muscle cell action potential potassium ion import across plasma membrane cardiac conduction sources:amigo / quickgoorthologsspecieshumanmouseentrez375916518ensemblensg00000123700ensmusg00000041695uniprotp63252p35561refseq (mrna)nm_000891nm_008425refseq (protein)np_000882np_032451location (ucsc)chr 17: 70.17 – 70.18 mbchr 11: 110.96 – 110.97 mbpubmed searchwikidataview/edit humanview/edit mouse clinical significance a defect in this gene is associated with andersen-tawil syndrome. a mutation in the kcnj2 gene has also been shown to cause short qt syndrome. in research in neurogenetics, kir2.1 is used in drosophila research to inhibit neurons, as overexpression of this channel will hyperpolarize cells. in optogenetics, a trafficking sequence from kir2.1 has been added to halorhodopsin to improve its membrane localization. the resulting protein enphr3.0 is used in optogenetic research to inhibit neurons with light. expression of kir2.1 gene in human hek293 cells induce a transient outward current, creating a steady membrane potential close to the reversal potential of potassium. interactions kir2.1 has been shown to interact with: dlg4, interleukin 16, and trak2