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Protein

Inward rectifier potassium channel 2

Gene

KCNJ2

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Probably 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.

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei172Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesiumBy similarity1

GO - Molecular functioni

GO - Biological processi

  • cardiac muscle cell action potential involved in contraction Source: BHF-UCL
  • cellular potassium ion homeostasis Source: BHF-UCL
  • cellular response to mechanical stimulus Source: Ensembl
  • magnesium ion transport Source: Ensembl
  • membrane depolarization during cardiac muscle cell action potential Source: BHF-UCL
  • membrane repolarization during action potential Source: BHF-UCL
  • membrane repolarization during cardiac muscle cell action potential Source: BHF-UCL
  • positive regulation of potassium ion transmembrane transport Source: Ensembl
  • potassium ion import Source: BHF-UCL
  • potassium ion transmembrane transport Source: BHF-UCL
  • potassium ion transport Source: UniProtKB
  • protein homotetramerization Source: UniProtKB
  • regulation of cardiac muscle cell contraction Source: Ensembl
  • regulation of heart rate by cardiac conduction Source: BHF-UCL
  • regulation of membrane repolarization Source: BHF-UCL
  • regulation of resting membrane potential Source: BHF-UCL
  • regulation of skeletal muscle contraction via regulation of action potential Source: BHF-UCL
  • relaxation of cardiac muscle Source: BHF-UCL
  • relaxation of skeletal muscle Source: BHF-UCL

Keywordsi

Molecular functionIon channel, Voltage-gated channel
Biological processIon transport, Potassium transport, Transport
LigandPotassium

Enzyme and pathway databases

ReactomeiR-HSA-1296041 Activation of G protein gated Potassium channels
R-HSA-1296053 Classical Kir channels
R-HSA-5576886 Phase 4 - resting membrane potential
R-HSA-997272 Inhibition of voltage gated Ca2+ channels via Gbeta/gamma subunits

Protein family/group databases

TCDBi1.A.2.1.2 the inward rectifier k(+) channel (irk-c) family

Names & Taxonomyi

Protein namesi
Recommended name:
Inward rectifier potassium channel 2
Alternative name(s):
Cardiac inward rectifier potassium channel
Inward rectifier K(+) channel Kir2.1
Short name:
IRK-1
Short name:
hIRK1
Potassium channel, inwardly rectifying subfamily J member 2
Gene namesi
Name:KCNJ2
Synonyms:IRK1
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 17

Organism-specific databases

EuPathDBiHostDB:ENSG00000123700.4
HGNCiHGNC:6263 KCNJ2
MIMi600681 gene
neXtProtiNX_P63252

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini2 – 81CytoplasmicBy similarityAdd BLAST80
Transmembranei82 – 106Helical; Name=M1By similarityAdd BLAST25
Topological domaini107 – 128ExtracellularBy similarityAdd BLAST22
Intramembranei129 – 140Helical; Pore-forming; Name=H5By similarityAdd BLAST12
Intramembranei141 – 147Pore-formingBy similarity7
Topological domaini148 – 156ExtracellularBy similarity9
Transmembranei157 – 178Helical; Name=M2By similarityAdd BLAST22
Topological domaini179 – 427CytoplasmicBy similarityAdd BLAST249

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Involvement in diseasei

Long QT syndrome 7 (LQT7)5 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA heart disorder characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress, and can present with a sentinel event of sudden cardiac death in infancy. Long QT syndrome type 7 manifests itself as a clinical triad consisting of potassium-sensitive periodic paralysis, ventricular ectopy and dysmorphic features.
See also OMIM:170390
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_06586154C → F in LQT7; there is loss of function when the mutant is expressed alone and a dominant-negative effect when expressed with wild-type channels; channel trafficking and assembly are not affected. 1 PublicationCorresponds to variant dbSNP:rs199473650EnsemblClinVar.1
Natural variantiVAR_01785167R → W in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894580EnsemblClinVar.1
Natural variantiVAR_01785271D → V in LQT7; loss of function mutation acting in a dominant-negative manner. 1 PublicationCorresponds to variant dbSNP:rs104894575EnsemblClinVar.1
Natural variantiVAR_06586275T → R in LQT7; loss of function mutation acting in a dominant-negative manner. 1 PublicationCorresponds to variant dbSNP:rs104894585EnsemblClinVar.1
Natural variantiVAR_01785395 – 98Missing in LQT7. 1 Publication4
Natural variantiVAR_017854186P → L in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894581EnsemblClinVar.1
Natural variantiVAR_017855216N → H in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894583EnsemblClinVar.1
Natural variantiVAR_017856218R → W in LQT7; loss of function and dominant-negative effect in current. 1 PublicationCorresponds to variant dbSNP:rs104894578EnsemblClinVar.1
Natural variantiVAR_017857300G → V in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894579EnsemblClinVar.1
Natural variantiVAR_017858302V → M in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894582EnsemblClinVar.1
Natural variantiVAR_065864305T → P in LQT7; there is loss of function when the mutant is expressed alone and a dominant-negative effect when expressed with wild-type channels; channel trafficking and assembly are not affected. 1 PublicationCorresponds to variant dbSNP:rs199473387EnsemblClinVar.1
Natural variantiVAR_017859314 – 315Missing in LQT7. 2
Short QT syndrome 3 (SQT3)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA heart disorder characterized by idiopathic persistently and uniformly short QT interval on ECG in the absence of structural heart disease in affected individuals. It causes syncope and sudden death. SQT3 has a unique ECG phenotype characterized by asymmetrical T waves.
See also OMIM:609622
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_023842172D → N in SQT3; gain of function. 1 PublicationCorresponds to variant dbSNP:rs104894584EnsemblClinVar.1
Atrial fibrillation, familial, 9 (ATFB9)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA familial form of atrial fibrillation, a common sustained cardiac rhythm disturbance. Atrial fibrillation is characterized by disorganized atrial electrical activity and ineffective atrial contraction promoting blood stasis in the atria and reduces ventricular filling. It can result in palpitations, syncope, thromboembolic stroke, and congestive heart failure.
See also OMIM:613980
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_06586393V → I in ATFB9; has a gain-of-function effect on the channels. 1 PublicationCorresponds to variant dbSNP:rs147750704EnsemblClinVar.1

Keywords - Diseasei

Atrial fibrillation, Disease mutation, Long QT syndrome, Short QT syndrome

Organism-specific databases

DisGeNETi3759
GeneReviewsiKCNJ2
MalaCardsiKCNJ2
MIMi170390 phenotype
609622 phenotype
613980 phenotype
OpenTargetsiENSG00000123700
Orphaneti37553 Cardiodysrhythmic potassium-sensitive periodic paralysis
334 Familial atrial fibrillation
51083 Familial short QT syndrome
PharmGKBiPA214

Chemistry databases

ChEMBLiCHEMBL1914276

Polymorphism and mutation databases

BioMutaiKCNJ2
DMDMi54037433

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Initiator methionineiRemoved1 Publication
ChainiPRO_00001549232 – 427Inward rectifier potassium channel 2Add BLAST426

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Lipidationi2N-myristoyl glycine1 Publication1
Modified residuei76S-nitrosocysteine1 Publication1

Post-translational modificationi

S-nitrosylation increases the open probability and inward rectifying currents.1 Publication

Keywords - PTMi

Lipoprotein, Myristate, S-nitrosylation

Proteomic databases

PaxDbiP63252
PeptideAtlasiP63252
PRIDEiP63252
ProteomicsDBi57513

PTM databases

iPTMnetiP63252
PhosphoSitePlusiP63252

Expressioni

Tissue specificityi

Heart, brain, placenta, lung, skeletal muscle, and kidney. Diffusely distributed throughout the brain.

Gene expression databases

BgeeiENSG00000123700
CleanExiHS_KCNJ2
GenevisibleiP63252 HS

Organism-specific databases

HPAiHPA029109

Interactioni

Subunit structurei

Homomultimeric and heteromultimeric association with KCNJ4/Kir2.3. Association, via its PDZ-recognition domain, with LIN7A, LIN7B, LIN7C, DLG1, CASK and APBA1 plays a key role in its localization and trafficking (By similarity).By similarity

GO - Molecular functioni

Protein-protein interaction databases

BioGridi109961, 3 interactors
ComplexPortaliCPX-3071 Inward rectifier potassium channel 2 complex
IntActiP63252, 7 interactors
STRINGi9606.ENSP00000243457

Chemistry databases

BindingDBiP63252

Structurei

3D structure databases

ProteinModelPortaliP63252
SMRiP63252
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi142 – 147Selectivity filterBy similarity6
Motifi425 – 427PDZ-bindingSequence analysis3

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG3827 Eukaryota
ENOG410XQ62 LUCA
GeneTreeiENSGT00760000118842
HOGENOMiHOG000237325
HOVERGENiHBG006178
InParanoidiP63252
KOiK04996
OMAiVFSHNAT
OrthoDBiEOG091G08HC
PhylomeDBiP63252
TreeFamiTF313676

Family and domain databases

Gene3Di2.60.40.1400, 2 hits
InterProiView protein in InterPro
IPR014756 Ig_E-set
IPR016449 K_chnl_inward-rec_Kir
IPR003271 K_chnl_inward-rec_Kir2.1
IPR013518 K_chnl_inward-rec_Kir_cyto
IPR013673 K_chnl_inward-rec_Kir_N
PANTHERiPTHR11767 PTHR11767, 1 hit
PTHR11767:SF43 PTHR11767:SF43, 1 hit
PfamiView protein in Pfam
PF01007 IRK, 1 hit
PF08466 IRK_N, 1 hit
PIRSFiPIRSF005465 GIRK_kir, 1 hit
PRINTSiPR01324 KIR21CHANNEL
PR01320 KIRCHANNEL
SUPFAMiSSF81296 SSF81296, 1 hit

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P63252-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MGSVRTNRYS IVSSEEDGMK LATMAVANGF GNGKSKVHTR QQCRSRFVKK
60 70 80 90 100
DGHCNVQFIN VGEKGQRYLA DIFTTCVDIR WRWMLVIFCL AFVLSWLFFG
110 120 130 140 150
CVFWLIALLH GDLDASKEGK ACVSEVNSFT AAFLFSIETQ TTIGYGFRCV
160 170 180 190 200
TDECPIAVFM VVFQSIVGCI IDAFIIGAVM AKMAKPKKRN ETLVFSHNAV
210 220 230 240 250
IAMRDGKLCL MWRVGNLRKS HLVEAHVRAQ LLKSRITSEG EYIPLDQIDI
260 270 280 290 300
NVGFDSGIDR IFLVSPITIV HEIDEDSPLY DLSKQDIDNA DFEIVVILEG
310 320 330 340 350
MVEATAMTTQ CRSSYLANEI LWGHRYEPVL FEEKHYYKVD YSRFHKTYEV
360 370 380 390 400
PNTPLCSARD LAEKKYILSN ANSFCYENEV ALTSKEEDDS ENGVPESTST
410 420
DTPPDIDLHN QASVPLEPRP LRRESEI
Length:427
Mass (Da):48,288
Last modified:October 11, 2004 - v1
Checksum:iAB37CAD4B99B4050
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti330L → F in AAC39555 (PubMed:9490857).Curated1
Sequence conflicti340D → E in AAC39555 (PubMed:9490857).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_06586154C → F in LQT7; there is loss of function when the mutant is expressed alone and a dominant-negative effect when expressed with wild-type channels; channel trafficking and assembly are not affected. 1 PublicationCorresponds to variant dbSNP:rs199473650EnsemblClinVar.1
Natural variantiVAR_01785167R → W in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894580EnsemblClinVar.1
Natural variantiVAR_01785271D → V in LQT7; loss of function mutation acting in a dominant-negative manner. 1 PublicationCorresponds to variant dbSNP:rs104894575EnsemblClinVar.1
Natural variantiVAR_06586275T → R in LQT7; loss of function mutation acting in a dominant-negative manner. 1 PublicationCorresponds to variant dbSNP:rs104894585EnsemblClinVar.1
Natural variantiVAR_06586393V → I in ATFB9; has a gain-of-function effect on the channels. 1 PublicationCorresponds to variant dbSNP:rs147750704EnsemblClinVar.1
Natural variantiVAR_01785395 – 98Missing in LQT7. 1 Publication4
Natural variantiVAR_023842172D → N in SQT3; gain of function. 1 PublicationCorresponds to variant dbSNP:rs104894584EnsemblClinVar.1
Natural variantiVAR_017854186P → L in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894581EnsemblClinVar.1
Natural variantiVAR_017855216N → H in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894583EnsemblClinVar.1
Natural variantiVAR_017856218R → W in LQT7; loss of function and dominant-negative effect in current. 1 PublicationCorresponds to variant dbSNP:rs104894578EnsemblClinVar.1
Natural variantiVAR_017857300G → V in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894579EnsemblClinVar.1
Natural variantiVAR_017858302V → M in LQT7. 1 PublicationCorresponds to variant dbSNP:rs104894582EnsemblClinVar.1
Natural variantiVAR_065864305T → P in LQT7; there is loss of function when the mutant is expressed alone and a dominant-negative effect when expressed with wild-type channels; channel trafficking and assembly are not affected. 1 PublicationCorresponds to variant dbSNP:rs199473387EnsemblClinVar.1
Natural variantiVAR_017859314 – 315Missing in LQT7. 2

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U24055 mRNA Translation: AAB50277.1
U12507 mRNA Translation: AAC50072.1
U16861 mRNA Translation: AAA91781.1
AF153819 Genomic DNA Translation: AAF73242.1
AF153820 mRNA Translation: AAF73241.1
U22413 mRNA Translation: AAA64282.1
AF011904 mRNA Translation: AAC39555.1
AF021139 mRNA Translation: AAB88797.1
CCDSiCCDS11688.1
PIRiI38727
RefSeqiNP_000882.1, NM_000891.2
UniGeneiHs.1547

Genome annotation databases

EnsembliENST00000243457; ENSP00000243457; ENSG00000123700
ENST00000535240; ENSP00000441848; ENSG00000123700
GeneIDi3759
KEGGihsa:3759
UCSCiuc002jir.4 human

Similar proteinsi

Entry informationi

Entry nameiKCNJ2_HUMAN
AccessioniPrimary (citable) accession number: P63252
Secondary accession number(s): O15110, P48049
Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 11, 2004
Last sequence update: October 11, 2004
Last modified: July 18, 2018
This is version 147 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. Human chromosome 17
    Human chromosome 17: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. SIMILARITY comments
    Index of protein domains and families

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