Kir2.1

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 70,168,673 bp End 70,180,044 bp
Gene location (Mouse) Chr. Chromosome 11 (mouse) Band 11 E2|11 75.23 cM Start 110,956,990 bp End 110,967,647 bp
RNA expression pattern 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 PubMed search
Wikidata
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The K_ir2.1 inward-rectifier potassium channel is a lipid-gated ion channel encoded by the KCNJ2 gene.

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

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. PMID 16382105. S2CID 11588492.
• 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. PMID 7590287.
• 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. PMID 7680768. S2CID 4243856.
• 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. PMID 7696590.
• 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. PMID 7840300.
• 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. PMID 8821791.
• 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. PMC 2230727. PMID 9490857.
• 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. PMID 9533862.
• 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. PMC 6782450. PMID 10479680.
• 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. PMID 10559219.
• 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. PMC 6774109. PMID 10627592.
• 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. PMID 11181181.
• 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. PMID 11240146. S2CID 14452157.
• 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. PMID 11287009. S2CID 19230587.
• 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. PMID 11287423.
• 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. PMID 11371347. S2CID 17015195.
• 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. PMID 11688996.
• 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. PMID 11809752.
• 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. PMC 124349. PMID 12032359.
• 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. PMID 12045162.

External links

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