Inward rectifier potassium channel 2

NameInward rectifier potassium channel 2
Synonyms
  • Cardiac inward rectifier potassium channel
  • hIRK1
  • Inward rectifier K(+) channel Kir2.1
  • IRK-1
  • IRK1
  • Potassium channel, inwardly rectifying subfamily J member 2
Gene NameKCNJ2
OrganismHuman
Amino acid sequence
>lcl|BSEQ0010179|Inward rectifier potassium channel 2
MGSVRTNRYSIVSSEEDGMKLATMAVANGFGNGKSKVHTRQQCRSRFVKKDGHCNVQFIN
VGEKGQRYLADIFTTCVDIRWRWMLVIFCLAFVLSWLFFGCVFWLIALLHGDLDASKEGK
ACVSEVNSFTAAFLFSIETQTTIGYGFRCVTDECPIAVFMVVFQSIVGCIIDAFIIGAVM
AKMAKPKKRNETLVFSHNAVIAMRDGKLCLMWRVGNLRKSHLVEAHVRAQLLKSRITSEG
EYIPLDQIDINVGFDSGIDRIFLVSPITIVHEIDEDSPLYDLSKQDIDNADFEIVVILEG
MVEATAMTTQCRSSYLANEILWGHRYEPVLFEEKHYYKVDYSRFHKTYEVPNTPLCSARD
LAEKKYILSNANSFCYENEVALTSKEEDDSENGVPESTSTDTPPDIDLHNQASVPLEPRP
LRRESEI
Number of residues427
Molecular Weight48287.82
Theoretical pI5.47
GO Classification
Functions
  • inward rectifier potassium channel activity
  • phosphatidylinositol-4,5-bisphosphate binding
  • voltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization
Processes
  • positive regulation of potassium ion transmembrane transport
  • relaxation of cardiac muscle
  • regulation of membrane repolarization
  • regulation of skeletal muscle contraction via regulation of action potential
  • potassium ion transport
  • relaxation of skeletal muscle
  • cardiac muscle cell action potential involved in contraction
  • membrane depolarization during cardiac muscle cell action potential
  • regulation of heart rate by cardiac conduction
  • synaptic transmission
  • cellular response to mechanical stimulus
  • protein homotetramerization
  • cellular potassium ion homeostasis
  • magnesium ion transport
  • potassium ion transmembrane transport
  • membrane repolarization during action potential
  • potassium ion import
  • membrane repolarization during cardiac muscle cell action potential
  • regulation of resting membrane potential
Components
  • intercalated disc
  • T-tubule
  • plasma membrane
  • voltage-gated potassium channel complex
  • neuronal cell body
  • Golgi apparatus
  • dendritic spine
  • integral component of plasma membrane
  • rough endoplasmic reticulum
  • smooth endoplasmic reticulum
  • intrinsic component of membrane
General FunctionVoltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization
Specific FunctionProbably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium or cesium.
Pfam Domain Function
Transmembrane Regions82-106 157-178
GenBank Protein ID833706
UniProtKB IDP63252
UniProtKB Entry NameKCNJ2_HUMAN
Cellular LocationMembrane
Gene sequence
>lcl|BSEQ0010180|Inward rectifier potassium channel 2 (KCNJ2)
ATGGGCAGTGTGCGAACCAACCGCTACAGCATCGTCTCTTCAGAAGAAGACGGTATGAAG
TTGGCCACCATGGCAGTTGCAAATGGCTTTGGGAACGGGAAGAGTAAAGTCCACACCCGA
CAACAGTGCAGGAGCCGCTTTGTGAAGAAAGATGGCCACTGTAATGTTCAGTTCATCAAT
GTGGGTGAGAAGGGGCAACGGTACCTCGCAGACATCTTCACCACGTGTGTGGACATTCGC
TGGCGGTGGATGCTGGTTATCTTCTGCCTGGCTTTCGTCCTGTCATGGCTGTTTTTTGGC
TGTGTGTTTTGGTTGATAGCTCTGCTCCATGGGGACCTGGATGCATCCAAAGAGGGCAAA
GCTTGTGTGTCCGAGGTCAACAGCTTCACGGCTGCCTTCCTCTTCTCCATTGAGACCCAG
ACAACCATAGGCTATGGTTTCAGATGTGTCACGGATGAATGCCCAATTGCTGTTTTCATG
GTGGTGTTCCAGTCAATCGTGGGCTGCATCATCGATGCTTTCATCATTGGCGCAGTCATG
GCCAAGATGGCAAAGCCAAAGAAGAGAAACGAGACTCTTGTCTTCAGTCACAATGCCGTG
ATTGCCATGAGAGACGGCAAGCTGTGTTTGATGTGGCGAGTGGGCAATCTTCGGAAAAGC
CACTTGGTGGAAGCTCATGTTCGAGCACAGCTCCTCAAATCCAGAATTACTTCTGAAGGG
GAGTATATCCCTCTGGATCAAATAGACATCAATGTTGGGTTTGACAGTGGAATCGATCGT
ATATTTCTGGTGTCCCCAATCACTATAGTCCATGAAATAGATGAAGACAGTCCTTTATAT
GATTTGAGTAAACAGGACATTGACAACGCAGACTTTGAAATCGTGGTCATACTGGAAGGC
ATGGTGGAAGCCACTGCCATGACGACACAGTGCCGTAGCTCTTATCTAGCAAATGAAATC
CTGTGGGGCCACCGCTATGAGCCTGTGCTCTTTGAAGAGAAGCACTACTACAAAGTGGAC
TATTCCAGGTTCCACAAAACTTACGAAGTCCCCAACACTCCCCTTTGTAGTGCCAGAGAC
TTAGCAGAAAAGAAATATATCCTCTCAAATGCAAATTCATTTTGCTATGAAAATGAAGTT
GCCCTCACAAGCAAAGAGGAAGACGACAGTGAAAATGGAGTTCCAGAAAGCACTAGTACG
GACACGCCCCCTGACATAGACCTTCACAACCAGGCAAGTGTACCTCTAGAGCCCAGGCCC
TTACGGCGAGAGTCGGAGATATGA
GenBank Gene IDU24055
GeneCard IDNot Available
GenAtlas IDKCNJ2
HGNC IDHGNC:6263
Chromosome Location17
Locus17q23.1-q24.2
References
  1. Raab-Graham KF, Radeke CM, Vandenberg CA: Molecular cloning and expression of a human heart inward rectifier potassium channel. Neuroreport. 1994 Dec 20;5(18):2501-5. 7696590
  2. Wood LS, Tsai TD, Lee KS, Vogeli G: Cloning and functional expression of a human gene, hIRK1, encoding the heart inward rectifier K+-channel. Gene. 1995 Oct 3;163(2):313-7. 7590287
  3. Tare M, Prestwich SA, Gordienko DV, Parveen S, Carver JE, Robinson C, Bolton TB: Inwardly rectifying whole cell potassium current in human blood eosinophils. J Physiol. 1998 Jan 15;506 ( Pt 2):303-18. 9490857
  4. Derst C, Karschin C, Wischmeyer E, Hirsch JR, Preisig-Muller R, Rajan S, Engel H, Grzeschik K, Daut J, Karschin A: Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits. FEBS Lett. 2001 Mar 2;491(3):305-11. 11240146
  5. Ashen MD, O'Rourke B, Kluge KA, Johns DC, Tomaselli GF: Inward rectifier K+ channel from human heart and brain: cloning and stable expression in a human cell line. Am J Physiol. 1995 Jan;268(1 Pt 2):H506-11. 7840300
  6. Preisig-Muller R, Schlichthorl G, Goerge T, Heinen S, Bruggemann A, Rajan S, Derst C, Veh RW, Daut J: Heteromerization of Kir2.x potassium channels contributes to the phenotype of Andersen's syndrome. Proc Natl Acad Sci U S A. 2002 May 28;99(11):7774-9. 12032359
  7. Gomez R, Caballero R, Barana A, Amoros I, Calvo E, Lopez JA, Klein H, Vaquero M, Osuna L, Atienza F, Almendral J, Pinto A, Tamargo J, Delpon E: Nitric oxide increases cardiac IK1 by nitrosylation of cysteine 76 of Kir2.1 channels. Circ Res. 2009 Aug 14;105(4):383-92. doi: 10.1161/CIRCRESAHA.109.197558. Epub 2009 Jul 16. 19608980
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  9. Plaster NM, Tawil R, Tristani-Firouzi M, Canun S, Bendahhou S, Tsunoda A, Donaldson MR, Iannaccone ST, Brunt E, Barohn R, Clark J, Deymeer F, George AL Jr, Fish FA, Hahn A, Nitu A, Ozdemir C, Serdaroglu P, Subramony SH, Wolfe G, Fu YH, Ptacek LJ: Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome. Cell. 2001 May 18;105(4):511-9. 11371347
  10. Andelfinger G, Tapper AR, Welch RC, Vanoye CG, George AL Jr, Benson DW: KCNJ2 mutation results in Andersen syndrome with sex-specific cardiac and skeletal muscle phenotypes. Am J Hum Genet. 2002 Sep;71(3):663-8. Epub 2002 Jul 29. 12148092
  11. Tristani-Firouzi M, Jensen JL, Donaldson MR, Sansone V, Meola G, Hahn A, Bendahhou S, Kwiecinski H, Fidzianska A, Plaster N, Fu YH, Ptacek LJ, Tawil R: Functional and clinical characterization of KCNJ2 mutations associated with LQT7 (Andersen syndrome). J Clin Invest. 2002 Aug;110(3):381-8. 12163457
  12. Xia M, Jin Q, Bendahhou S, He Y, Larroque MM, Chen Y, Zhou Q, Yang Y, Liu Y, Liu B, Zhu Q, Zhou Y, Lin J, Liang B, Li L, Dong X, Pan Z, Wang R, Wan H, Qiu W, Xu W, Eurlings P, Barhanin J, Chen Y: A Kir2.1 gain-of-function mutation underlies familial atrial fibrillation. Biochem Biophys Res Commun. 2005 Jul 15;332(4):1012-9. 15922306
  13. Priori SG, Pandit SV, Rivolta I, Berenfeld O, Ronchetti E, Dhamoon A, Napolitano C, Anumonwo J, di Barletta MR, Gudapakkam S, Bosi G, Stramba-Badiale M, Jalife J: A novel form of short QT syndrome (SQT3) is caused by a mutation in the KCNJ2 gene. Circ Res. 2005 Apr 15;96(7):800-7. Epub 2005 Mar 10. 15761194
  14. Lu CW, Lin JH, Rajawat YS, Jerng H, Rami TG, Sanchez X, DeFreitas G, Carabello B, DeMayo F, Kearney DL, Miller G, Li H, Pfaffinger PJ, Bowles NE, Khoury DS, Towbin JA: Functional and clinical characterization of a mutation in KCNJ2 associated with Andersen-Tawil syndrome. J Med Genet. 2006 Aug;43(8):653-9. Epub 2006 Mar 29. 16571646
  15. Bendahhou S, Fournier E, Gallet S, Menard D, Larroque MM, Barhanin J: Corticosteroid-exacerbated symptoms in an Andersen's syndrome kindred. Hum Mol Genet. 2007 Apr 15;16(8):900-6. Epub 2007 Feb 26. 17324964