Skip Header

You are using a version of Internet Explorer that may not display all features of this website. Please upgrade to a modern browser.
Contribute Send feedback
Read comments (?) or add your own

Q64273 (IRK2_RAT) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 119. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended 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 names
Name:Kcnj2
Synonyms:Irk1
OrganismRattus norvegicus (Rat) [Reference proteome]
Taxonomic identifier10116 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus

Protein attributes

Sequence length427 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

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. Ref.3

Subunit structure

Homomultimeric and heteromultimeric association with Kir2.3, resulting in an enhanced G-protein-induced current. Association, via its PDZ-recognition domain, with LIN7A, LIN7B, LIN7C, DLG1, CASK and APBA1 plays a key role in its localization and trafficking.

Subcellular location

Membrane; Multi-pass membrane protein.

Tissue specificity

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

Post-translational modification

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

Sequence similarities

Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ2 subfamily. [View classification]

Ontologies

Keywords
   Biological processIon transport
Potassium transport
Transport
   Cellular componentMembrane
   DomainTransmembrane
Transmembrane helix
   LigandPotassium
   Molecular functionIon channel
Voltage-gated channel
   PTMS-nitrosylation
   Technical termComplete proteome
Reference proteome
Gene Ontology (GO)
   Biological_processcardiac muscle cell action potential involved in contraction

Inferred from electronic annotation. Source: Ensembl

cellular response to mechanical stimulus

Inferred from expression pattern PubMed 17293496. Source: RGD

magnesium ion transport

Inferred from electronic annotation. Source: Ensembl

positive regulation of potassium ion transmembrane transport

Inferred from mutant phenotype PubMed 22426100. Source: RGD

potassium ion import

Inferred from electronic annotation. Source: Ensembl

potassium ion transport

Inferred from sequence or structural similarity. Source: UniProtKB

protein homotetramerization

Inferred from sequence or structural similarity. Source: UniProtKB

regulation of cardiac muscle cell contraction

Inferred from mutant phenotype PubMed 22426100. Source: RGD

regulation of heart rate by cardiac conduction

Inferred from electronic annotation. Source: Ensembl

regulation of membrane repolarization

Inferred from electronic annotation. Source: Ensembl

regulation of skeletal muscle contraction via regulation of action potential

Inferred from electronic annotation. Source: Ensembl

relaxation of cardiac muscle

Inferred from electronic annotation. Source: Ensembl

relaxation of skeletal muscle

Inferred from electronic annotation. Source: Ensembl

   Cellular_componentGolgi apparatus

Inferred from direct assay PubMed 18076085. Source: RGD

T-tubule

Inferred from direct assay PubMed 23640888. Source: RGD

dendrite

Inferred from direct assay PubMed 12591157. Source: RGD

dendritic spine

Inferred from direct assay PubMed 18076085. Source: RGD

intercalated disc

Inferred from direct assay PubMed 23640888. Source: RGD

intrinsic component of membrane

Inferred from sequence or structural similarity. Source: UniProtKB

neuronal cell body

Inferred from direct assay PubMed 12591157. Source: RGD

plasma membrane

Inferred from direct assay PubMed 18076085. Source: RGD

rough endoplasmic reticulum

Inferred from direct assay PubMed 18076085. Source: RGD

smooth endoplasmic reticulum

Inferred from direct assay PubMed 18076085. Source: RGD

voltage-gated potassium channel complex

Inferred from electronic annotation. Source: Ensembl

   Molecular_functioninward rectifier potassium channel activity

Inferred from sequence or structural similarity. Source: UniProtKB

phosphatidylinositol-4,5-bisphosphate binding

Inferred from electronic annotation. Source: Ensembl

voltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization

Inferred from electronic annotation. Source: Ensembl

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 427427Inward rectifier potassium channel 2
PRO_0000154928

Regions

Topological domain1 – 8181Cytoplasmic By similarity
Transmembrane82 – 10625Helical; Name=M1; By similarity
Topological domain107 – 12822Extracellular By similarity
Intramembrane129 – 14012Helical; Pore-forming; Name=H5; By similarity
Intramembrane141 – 1477Pore-forming; By similarity
Topological domain148 – 1569Extracellular By similarity
Transmembrane157 – 17822Helical; Name=M2; By similarity
Topological domain179 – 427249Cytoplasmic By similarity
Motif142 – 1476Selectivity filter By similarity
Motif425 – 4273PDZ-binding Potential

Sites

Site1721Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesium By similarity

Amino acid modifications

Modified residue761S-nitrosocysteine By similarity

Sequences

Sequence LengthMass (Da)Tools
Q64273 [UniParc].

Last modified November 1, 1996. Version 1.
Checksum: 85538FB1CCEBF8ED

FASTA42748,200
        10         20         30         40         50         60 
MGSVRTNRYS IVSSEEDGMK LATMAVANGF GNGKSKVHTR QQCRSRFVKK DGHCNVQFIN 

        70         80         90        100        110        120 
VGEKGQRYLA DIFTTCVDIR WRWMLVIFCL AFVLSWLFFG CVFWLIALLH GDLDASKESK 

       130        140        150        160        170        180 
ACVSEVNSFT AAFLFSIETQ TTIGYGFRCV TDECPIAVFM VVFQSIVGCI IDAFIIGAVM 

       190        200        210        220        230        240 
AKMAKPKKRN ETLVFSHNAV IAMRDGKLCL MWRVGNLRKS HLVEAHVRAQ LLKSRITSEG 

       250        260        270        280        290        300 
EYIPLDQIDI NVGFDSGIDR IFLVSPITIV HEIDEDSPLY DLSKQDIDNA DFEIVVILEG 

       310        320        330        340        350        360 
MVEATAMTTQ CRSSYLANEI LWGHRYEPVL FEEKHCYKVD YSRFHKTYEV PNTPLCSARD 

       370        380        390        400        410        420 
LAEKKYILSN ANSFCYENEV ALTSKEEEDS ENGVPESTST DSPPGIDLHN QASVPLEPRP 


LRRESEI 

« Hide

References

[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.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
L48490 mRNA. Translation: AAB03890.1.
AF021137 mRNA. Translation: AAB88795.1.
RefSeqNP_058992.1. NM_017296.1.
XP_006247629.1. XM_006247567.1.
UniGeneRn.44415.

3D structure databases

ProteinModelPortalQ64273.
SMRQ64273. Positions 187-370.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

DIPDIP-33299N.
IntActQ64273. 1 interaction.
STRING10116.ENSRNOP00000006254.

Proteomic databases

PaxDbQ64273.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENSRNOT00000006254; ENSRNOP00000006254; ENSRNOG00000004720.
GeneID29712.
KEGGrno:29712.

Organism-specific databases

CTD3759.
RGD61968. Kcnj2.

Phylogenomic databases

eggNOGNOG72812.
GeneTreeENSGT00650000093228.
HOGENOMHOG000237325.
HOVERGENHBG006178.
InParanoidQ64273.
KOK04996.
OMAHNATVAM.
OrthoDBEOG7XPZ5K.
PhylomeDBQ64273.
TreeFamTF313676.

Gene expression databases

GenevestigatorQ64273.

Family and domain databases

Gene3D2.60.40.1400. 1 hit.
InterProIPR014756. 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]
PANTHERPTHR11767. PTHR11767. 1 hit.
PTHR11767:SF15. PTHR11767:SF15. 1 hit.
PfamPF01007. IRK. 1 hit.
PF08466. IRK_N. 1 hit.
[Graphical view]
PIRSFPIRSF005465. GIRK_kir. 1 hit.
PRINTSPR01324. KIR21CHANNEL.
PR01320. KIRCHANNEL.
SUPFAMSSF81296. SSF81296. 1 hit.
ProtoNetSearch...

Other

NextBio610149.
PROQ64273.

Entry information

Entry nameIRK2_RAT
AccessionPrimary (citable) accession number: Q64273
Entry history
Integrated into UniProtKB/Swiss-Prot: November 1, 1997
Last sequence update: November 1, 1996
Last modified: April 16, 2014
This is version 119 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families