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Protein

Inward rectifier potassium channel 2

Gene

Kcnj2

Organism
Rattus norvegicus (Rat)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-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 and cesium (By similarity).By similarity

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sitei172 – 1721Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesiumBy similarity

GO - Molecular functioni

  1. inward rectifier potassium channel activity Source: UniProtKB
  2. phosphatidylinositol-4,5-bisphosphate binding Source: Ensembl
  3. voltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization Source: Ensembl

GO - Biological processi

  1. cardiac muscle cell action potential involved in contraction Source: Ensembl
  2. cellular response to mechanical stimulus Source: RGD
  3. magnesium ion transport Source: Ensembl
  4. positive regulation of potassium ion transmembrane transport Source: RGD
  5. potassium ion import Source: GO_Central
  6. potassium ion transport Source: UniProtKB
  7. protein homotetramerization Source: UniProtKB
  8. regulation of cardiac muscle cell contraction Source: RGD
  9. regulation of heart rate by cardiac conduction Source: Ensembl
  10. regulation of membrane repolarization Source: Ensembl
  11. regulation of skeletal muscle contraction via regulation of action potential Source: Ensembl
  12. relaxation of cardiac muscle Source: Ensembl
  13. relaxation of skeletal muscle Source: Ensembl
Complete GO annotation...

Keywords - Molecular functioni

Ion channel, Voltage-gated channel

Keywords - Biological processi

Ion transport, Potassium transport, Transport

Keywords - Ligandi

Potassium

Enzyme and pathway databases

ReactomeiREACT_278318. Activation of G protein gated Potassium channels.
REACT_287906. Inhibition of voltage gated Ca2+ channels via Gbeta/gamma subunits.
REACT_292836. Classical Kir channels.

Names & Taxonomyi

Protein namesi
Recommended name:
Inward rectifier potassium channel 2
Alternative name(s):
Inward rectifier K(+) channel Kir2.1
Short name:
IRK-1
Short name:
RBL-IRK1
Potassium channel, inwardly rectifying subfamily J member 2
Gene namesi
Name:Kcnj2
Synonyms:Irk1
OrganismiRattus norvegicus (Rat)
Taxonomic identifieri10116 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus
ProteomesiUP000002494 Componenti: Chromosome 10

Organism-specific databases

RGDi61968. Kcnj2.

Subcellular locationi

  1. Membrane; Multi-pass membrane protein
  2. Membrane; Lipid-anchor By similarity

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini2 – 8180CytoplasmicBy similarityAdd
BLAST
Transmembranei82 – 10625Helical; Name=M1By similarityAdd
BLAST
Topological domaini107 – 12822ExtracellularBy similarityAdd
BLAST
Intramembranei129 – 14012Helical; Pore-forming; Name=H5By similarityAdd
BLAST
Intramembranei141 – 1477Pore-formingBy similarity
Topological domaini148 – 1569ExtracellularBy similarity
Transmembranei157 – 17822Helical; Name=M2By similarityAdd
BLAST
Topological domaini179 – 427249CytoplasmicBy similarityAdd
BLAST

GO - Cellular componenti

  1. dendrite Source: RGD
  2. dendritic spine Source: RGD
  3. Golgi apparatus Source: RGD
  4. integral component of plasma membrane Source: GO_Central
  5. intercalated disc Source: RGD
  6. intrinsic component of membrane Source: UniProtKB
  7. neuronal cell body Source: RGD
  8. plasma membrane Source: RGD
  9. rough endoplasmic reticulum Source: RGD
  10. smooth endoplasmic reticulum Source: RGD
  11. T-tubule Source: RGD
  12. voltage-gated potassium channel complex Source: Ensembl
Complete GO annotation...

Keywords - Cellular componenti

Membrane

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Initiator methioninei1 – 11Removed
Chaini2 – 427426Inward rectifier potassium channel 2PRO_0000154928Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Lipidationi2 – 21N-myristoyl glycineBy similarity
Modified residuei76 – 761S-nitrosocysteineBy similarity

Post-translational modificationi

S-nitrosylation increases the open probabilty and inward rectifying currents.By similarity

Keywords - PTMi

Lipoprotein, Myristate, S-nitrosylation

Proteomic databases

PaxDbiQ64273.

Expressioni

Tissue specificityi

Prominently expressed in the central nervous system. Also found in other excitable tissues such as heart and skeletal muscle.

Gene expression databases

GenevestigatoriQ64273.

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.

Protein-protein interaction databases

DIPiDIP-33299N.
IntActiQ64273. 1 interaction.
STRINGi10116.ENSRNOP00000006254.

Structurei

3D structure databases

ProteinModelPortaliQ64273.
SMRiQ64273. Positions 187-370.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Motif

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Motifi142 – 1476Selectivity filterBy similarity
Motifi425 – 4273PDZ-bindingSequence Analysis

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiNOG72812.
GeneTreeiENSGT00760000118842.
HOGENOMiHOG000237325.
HOVERGENiHBG006178.
InParanoidiQ64273.
KOiK04996.
OMAiHNATVAM.
OrthoDBiEOG7XPZ5K.
PhylomeDBiQ64273.
TreeFamiTF313676.

Family and domain databases

Gene3Di2.60.40.1400. 1 hit.
InterProiIPR014756. 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.
[Graphical view]
PANTHERiPTHR11767. PTHR11767. 1 hit.
PfamiPF01007. IRK. 1 hit.
PF08466. IRK_N. 1 hit.
[Graphical view]
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.

Q64273-1 [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 GDLDASKESK 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 FEEKHCYKVD YSRFHKTYEV
360 370 380 390 400
PNTPLCSARD LAEKKYILSN ANSFCYENEV ALTSKEEEDS ENGVPESTST
410 420
DSPPGIDLHN QASVPLEPRP LRRESEI
Length:427
Mass (Da):48,200
Last modified:November 1, 1996 - v1
Checksum:i85538FB1CCEBF8ED
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L48490 mRNA. Translation: AAB03890.1.
AF021137 mRNA. Translation: AAB88795.1.
RefSeqiNP_058992.1. NM_017296.1.
XP_006247629.1. XM_006247567.2.
UniGeneiRn.44415.

Genome annotation databases

EnsembliENSRNOT00000006254; ENSRNOP00000006254; ENSRNOG00000004720.
GeneIDi29712.
KEGGirno:29712.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L48490 mRNA. Translation: AAB03890.1.
AF021137 mRNA. Translation: AAB88795.1.
RefSeqiNP_058992.1. NM_017296.1.
XP_006247629.1. XM_006247567.2.
UniGeneiRn.44415.

3D structure databases

ProteinModelPortaliQ64273.
SMRiQ64273. Positions 187-370.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

DIPiDIP-33299N.
IntActiQ64273. 1 interaction.
STRINGi10116.ENSRNOP00000006254.

Proteomic databases

PaxDbiQ64273.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENSRNOT00000006254; ENSRNOP00000006254; ENSRNOG00000004720.
GeneIDi29712.
KEGGirno:29712.

Organism-specific databases

CTDi3759.
RGDi61968. Kcnj2.

Phylogenomic databases

eggNOGiNOG72812.
GeneTreeiENSGT00760000118842.
HOGENOMiHOG000237325.
HOVERGENiHBG006178.
InParanoidiQ64273.
KOiK04996.
OMAiHNATVAM.
OrthoDBiEOG7XPZ5K.
PhylomeDBiQ64273.
TreeFamiTF313676.

Enzyme and pathway databases

ReactomeiREACT_278318. Activation of G protein gated Potassium channels.
REACT_287906. Inhibition of voltage gated Ca2+ channels via Gbeta/gamma subunits.
REACT_292836. Classical Kir channels.

Miscellaneous databases

NextBioi610149.
PROiQ64273.

Gene expression databases

GenevestigatoriQ64273.

Family and domain databases

Gene3Di2.60.40.1400. 1 hit.
InterProiIPR014756. 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.
[Graphical view]
PANTHERiPTHR11767. PTHR11767. 1 hit.
PfamiPF01007. IRK. 1 hit.
PF08466. IRK_N. 1 hit.
[Graphical view]
PIRSFiPIRSF005465. GIRK_kir. 1 hit.
PRINTSiPR01324. KIR21CHANNEL.
PR01320. KIRCHANNEL.
SUPFAMiSSF81296. SSF81296. 1 hit.
ProtoNetiSearch...

Publicationsi

  1. "Physiological and molecular characterization of an IRK-type inward rectifier K+ channel in a tumour mast cell line."
    Wischmeyer E., Lentes K.U., Karschin A.
    Pflugers Arch. 429:809-819(1995) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
  2. "Inwardly rectifying potassium channels in lens epithelium are from the IRK1 (Kir 2.1) family."
    Rae J.L., Shepard A.R.
    Exp. Eye Res. 66:347-359(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
    Strain: Sprague-Dawley.
    Tissue: Lens epithelium.
  3. "A multiprotein trafficking complex composed of SAP97, CASK, Veli, and Mint1 is associated with inward rectifier Kir2 potassium channels."
    Leonoudakis D., Conti L.R., Radeke C.M., McGuire L.M., Vandenberg C.A.
    J. Biol. Chem. 279:19051-19063(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: INTERACTION WITH CASK; LIN7A; LIN7B; LIN7C; APBA1 AND DLG1, FUNCTION.

Entry informationi

Entry nameiKCNJ2_RAT
AccessioniPrimary (citable) accession number: Q64273
Entry historyi
Integrated into UniProtKB/Swiss-Prot: November 1, 1997
Last sequence update: November 1, 1996
Last modified: April 1, 2015
This is version 129 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.