Kir2.1

TheK_ir2.1inward-rectifier potassium channelis alipid-gated ion channelencoded by theKCNJ2gene.

KCNJ2
Identifiers
Aliases	KCNJ2,ATFB9, HHBIRK1, HHIRK1, IRK1, KIR2.1, LQT7, SQT3, potassium voltage-gated channel subfamily J member 2, potassium inwardly rectifying channel subfamily J member 2
External IDs	OMIM:600681;MGI:104744;HomoloGene:20249;GeneCards:KCNJ2;OMA:KCNJ2 - orthologs
Gene location (Human) Chr. Chromosome 17 (human) Band 17q24.3 Start 70,168,673bp End 70,180,044bp
Gene location (Mouse) Chr. Chromosome 11 (mouse) Band 11 E2|11 75.23 cM Start 110,956,990bp End 110,967,647bp
RNA expressionpattern Bgee Human Mouse(ortholog) Top expressed in inferior ganglion of vagus nerve Skeletal muscle tissue of rectus abdominis dorsal motor nucleus of vagus nerve Skeletal muscle tissue of biceps brachii pons myocardium of left ventricle subthalamic nucleus corpus callosum superior vestibular nucleus inferior olivary nucleus Top expressed in muscle of thigh granulocyte genital tubercle superior frontal gyrus lip primary visual cortex temporal muscle dentate gyrus of hippocampal formation granule cell esophagus upper arm More reference expression data BioGPS More reference expression data
Gene ontology Molecular 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 soma 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/QuickGO
Orthologs Species Human Mouse Entrez 3759 16518 Ensembl ENSG00000123700 ENSMUSG00000041695 UniProt P63252 P35561 RefSeq (mRNA) NM_000891 NM_008425 RefSeq (protein) NP_000882 NP_032451 Location (UCSC) Chr 17: 70.17 – 70.18 Mb Chr 11: 110.96 – 110.97 Mb PubMedsearch
Wikidata
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Clinical significance

A defect in this gene is associated withAndersen-Tawil syndrome.

A mutation in the KCNJ2 gene has also been shown to causeshort QT syndrome.

In research

In neurogenetics, Kir2.1 is used inDrosophilaresearch to inhibit neurons, as overexpression of this channel willhyperpolarizecells.

In optogenetics, a trafficking sequence from Kir2.1 has been added tohalorhodopsinto improve its membrane localization. The resulting protein eNpHR3.0 is used inoptogenetic researchto inhibit neurons with light.

Expression of Kir2.1 gene in humanHEK293 cellsinduce a transient outward current, creating a steadymembrane potentialclose to thereversal potentialof potassium.

Interactions

Kir2.1 has been shown tointeractwith:

• DLG4,
• Interleukin 16,and
• TRAK2

Further reading

• Kubo Y, Adelman JP, Clapham DE, et al. (2006). "International Union of Pharmacology. LIV. Nomenclature and molecular relationships of inwardly rectifying potassium channels".Pharmacol. Rev.57(4): 509–26.doi:10.1124/pr.57.4.11.PMID16382105.S2CID11588492.
• Wood LS, Tsai TD, Lee KS, Vogeli G (1995). "Cloning and functional expression of a human gene, hIRK1, encoding the heart inward rectifier K+-channel".Gene.163(2): 313–7.doi:10.1016/0378-1119(95)00244-Z.PMID7590287.
• Kubo Y, Baldwin TJ, Jan YN, Jan LY (1993). "Primary structure and functional expression of a mouse inward rectifier potassium channel".Nature.362(6416): 127–33.Bibcode:1993Natur.362..127K.doi:10.1038/362127a0.PMID7680768.S2CID4243856.
• Raab-Graham KF, Radeke CM, Vandenberg CA (1995). "Molecular cloning and expression of a human heart inward rectifier potassium channel".NeuroReport.5(18): 2501–5.doi:10.1097/00001756-199412000-00024.PMID7696590.
• Ashen MD, O'Rourke B, Kluge KA, et al. (1995). "Inward rectifier K+ channel from human heart and brain: cloning and stable expression in a human cell line".Am. J. Physiol.268(1 Pt 2): H506–11.doi:10.1152/ajpheart.1995.268.1.H506.PMID7840300.
• Tang W, Qin CL, Yang XC (1996). "Cloning, localization, and functional expression of a human brain inward rectifier potassium channel (hIRK1)".Recept. Channels.3(3): 175–83.PMID8821791.
• Tare M, Prestwich SA, Gordienko DV, et al. (1998)."Inwardly rectifying whole cell potassium current in human blood eosinophils".J. Physiol.506(2): 303–18.doi:10.1111/j.1469-7793.1998.303bw.x.PMC2230727.PMID9490857.
• Rae JL, Shepard AR (1998). "Inwardly rectifying potassium channels in lens epithelium are from the IRK1 (Kir 2.1) family".Exp. Eye Res.66(3): 347–59.doi:10.1006/exer.1997.0432.PMID9533862.
• Kurschner C, Yuzaki M (1999)."Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein".J. Neurosci.19(18): 7770–80.doi:10.1523/JNEUROSCI.19-18-07770.1999.PMC6782450.PMID10479680.
• Tucker SJ, Ashcroft FM (1999)."Mapping of the physical interaction between the intracellular domains of an inwardly rectifying potassium channel, Kir6.2".J. Biol. Chem.274(47): 33393–7.doi:10.1074/jbc.274.47.33393.PMID10559219.
• Nehring RB, Wischmeyer E, Döring F, et al. (2000)."Neuronal inwardly rectifying K(+) channels differentially couple to PDZ proteins of the PSD-95/SAP90 family".J. Neurosci.20(1): 156–62.doi:10.1523/JNEUROSCI.20-01-00156.2000.PMC6774109.PMID10627592.
• Leonoudakis D, Mailliard W, Wingerd K, et al. (2001)."Inward rectifier potassium channel Kir2.2 is associated with synapse-associated protein SAP97".J. Cell Sci.114(Pt 5): 987–98.doi:10.1242/jcs.114.5.987.PMID11181181.
• Derst C, Karschin C, Wischmeyer E, et al. (2001). "Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits".FEBS Lett.491(3): 305–11.Bibcode:2001FEBSL.491..305D.doi:10.1016/S0014-5793(01)02202-5.PMID11240146.S2CID14452157.
• Stockklausner C, Ludwig J, Ruppersberg JP, Klöcker N (2001)."A sequence motif responsible for ER export and surface expression of Kir2.0 inward rectifier K(+) channels".FEBS Lett.493(2–3): 129–33.Bibcode:2001FEBSL.493..129S.doi:10.1016/S0014-5793(01)02286-4.PMID11287009.S2CID19230587.
• Dart C, Leyland ML (2001)."Targeting of an A kinase-anchoring protein, AKAP79, to an inwardly rectifying potassium channel, Kir2.1".J. Biol. Chem.276(23): 20499–505.doi:10.1074/jbc.M101425200.PMID11287423.
• Plaster NM, Tawil R, Tristani-Firouzi M, et al. (2001)."Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome".Cell.105(4): 511–9.doi:10.1016/S0092-8674(01)00342-7.PMID11371347.S2CID17015195.
• Jeong JS, Lee HJ, Jung JS, et al. (2001). "Characterization of inwardly rectifying K(+) conductance across the basolateral membrane of rat tracheal epithelia".Biochem. Biophys. Res. Commun.288(4): 914–20.doi:10.1006/bbrc.2001.5831.PMID11688996.
• Giovannardi S, Forlani G, Balestrini M, et al. (2002)."Modulation of the inward rectifier potassium channel IRK1 by the Ras signaling pathway".J. Biol. Chem.277(14): 12158–63.doi:10.1074/jbc.M110466200.PMID11809752.
• Preisig-Müller R, Schlichthörl G, Goerge T, et al. (2002)."Heteromerization of Kir2.x potassium channels contributes to the phenotype of Andersen's syndrome".Proc. Natl. Acad. Sci. U.S.A.99(11): 7774–9.Bibcode:2002PNAS...99.7774P.doi:10.1073/pnas.102609499.PMC124349.PMID12032359.
• Ai T, Fujiwara Y, Tsuji K, et al. (2002)."Novel KCNJ2 mutation in familial periodic paralysis with ventricular dysrhythmia".Circulation.105(22): 2592–4.doi:10.1161/01.CIR.0000019906.35135.A3.PMID12045162.

External links

• GeneReviews/NCBI/NIH/UW entry on Andersen-Tawil syndrome
• OMIM entries on Anderson-Tawil syndrome
• KCNJ2+protein,+humanat the U.S. National Library of MedicineMedical Subject Headings(MeSH)
• Kir2.1+channelat the U.S. National Library of MedicineMedical Subject Headings(MeSH)