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P35561 (IRK2_MOUSE) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 134. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Interactions·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
Potassium channel, inwardly rectifying subfamily J member 2
Gene names
Name:Kcnj2
Synonyms:Irk1
OrganismMus musculus (Mouse) [Reference proteome]
Taxonomic identifier10090 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeMusMus

Protein attributes

Sequence length428 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.

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 By similarity.

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 term3D-structure
Complete proteome
Reference proteome
Gene Ontology (GO)
   Biological_processcardiac muscle cell action potential

Inferred from mutant phenotype PubMed 15581370. Source: MGI

cardiac muscle cell action potential involved in contraction

Inferred from electronic annotation. Source: Ensembl

cellular response to mechanical stimulus

Inferred from electronic annotation. Source: Ensembl

magnesium ion transport

Inferred from direct assay PubMed 8189383. Source: MGI

positive regulation of potassium ion transmembrane transport

Inferred from electronic annotation. Source: Ensembl

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 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 electronic annotation. Source: Ensembl

T-tubule

Inferred from electronic annotation. Source: Ensembl

dendritic spine

Inferred from electronic annotation. Source: Ensembl

intercalated disc

Inferred from electronic annotation. Source: Ensembl

intrinsic component of membrane

Inferred from sequence or structural similarity. Source: UniProtKB

neuronal cell body

Inferred from electronic annotation. Source: Ensembl

rough endoplasmic reticulum

Inferred from electronic annotation. Source: Ensembl

smooth endoplasmic reticulum

Inferred from electronic annotation. Source: Ensembl

voltage-gated potassium channel complex

Inferred from electronic annotation. Source: Ensembl

   Molecular_functionidentical protein binding

Inferred from physical interaction PubMed 21703452. Source: IntAct

inward 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...

Binary interactions

With

Entry

#Exp.

IntAct

Notes

itself4EBI-703793,EBI-703793
AKAP5P245882EBI-703793,EBI-703640From a different organism.
Ap1g1B2RYN62EBI-703793,EBI-4319005From a different organism.
DLG2Q15700-46EBI-703793,EBI-663057From a different organism.
FLNAQ2YHQ33EBI-703793,EBI-779542From a different organism.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 428428Inward rectifier potassium channel 2
PRO_0000154925

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 – 428250Cytoplasmic By similarity
Motif142 – 1476Selectivity filter By similarity
Motif426 – 4283PDZ-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

Experimental info

Mutagenesis751T → R: The mutant protein is able to coassemble and traffic to the cell membrane. Ref.4

Secondary structure

........................................... 428
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
P35561 [UniParc].

Last modified June 1, 1994. Version 1.
Checksum: 5B4219F979BBA41C

FASTA42848,389
        10         20         30         40         50         60 
MGSVRTNRYS IVSSEEDGMK LATMAVANGF GNGKSKVHTR QQCRSRFVKK DGHCNVQFIN 

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

       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 FEEKHYYKVD YSRFHKTYEV PNTPLCSARD 

       370        380        390        400        410        420 
LAEKKYILSN ANSFCYENEV ALTSKEEEED SENGVPESTS TDSPPGIDLH NQASVPLEPR 


PLRRESEI 

« Hide

References

« Hide 'large scale' references
[1]"Primary structure and functional expression of a mouse inward rectifier potassium channel."
Kubo Y., Baldwin T.J., Jan Y.N., Jan L.Y.
Nature 362:127-132(1993) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA].
Strain: BALB/c.
Tissue: Macrophage.
[2]"Molecular cloning, functional expression and localization of an inward rectifier potassium channel in the mouse brain."
Morishige K., Takahashi N., Findlay I., Koyama H., Zanelli J.S., Peterson C., Jenkins N.A., Copeland N.G., Mori N., Kurachi Y.
FEBS Lett. 336:375-380(1993) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA].
Tissue: Brain.
[3]"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].
Tissue: Lens epithelium.
[4]"Functional and clinical characterization of a mutation in KCNJ2 associated with Andersen-Tawil syndrome."
Lu C.W., Lin J.H., Rajawat Y.S., Jerng H., Rami T.G., Sanchez X., DeFreitas G., Carabello B., DeMayo F., Kearney D.L., Miller G., Li H., Pfaffinger P.J., Bowles N.E., Khoury D.S., Towbin J.A.
J. Med. Genet. 43:653-659(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF THR-75.
[5]"The phagosomal proteome in interferon-gamma-activated macrophages."
Trost M., English L., Lemieux S., Courcelles M., Desjardins M., Thibault P.
Immunity 30:143-154(2009) [PubMed] [Europe PMC] [Abstract]
Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
X73052 mRNA. Translation: CAA51526.1.
AF021136 mRNA. Translation: AAB88794.1.
PIRS32351.
RefSeqNP_032451.1. NM_008425.4.
UniGeneMm.4951.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
1U4FX-ray2.41A/B/C/D41-428[»]
2GIXX-ray2.02A/B/C/D44-371[»]
2XKYOther17.20I/J/K/L1-428[»]
ProteinModelPortalP35561.
SMRP35561. Positions 43-371.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

BioGrid200900. 1 interaction.
IntActP35561. 11 interactions.
MINTMINT-104054.
STRING10090.ENSMUSP00000037192.

Chemistry

BindingDBP35561.
ChEMBLCHEMBL1293290.
GuidetoPHARMACOLOGY430.

PTM databases

PhosphoSiteP35561.

Proteomic databases

PaxDbP35561.
PRIDEP35561.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENSMUST00000042970; ENSMUSP00000037192; ENSMUSG00000041695.
GeneID16518.
KEGGmmu:16518.
UCSCuc007mdw.2. mouse.

Organism-specific databases

CTD3759.
MGIMGI:104744. Kcnj2.

Phylogenomic databases

eggNOGNOG72812.
HOGENOMHOG000237325.
HOVERGENHBG006178.
InParanoidP35561.
KOK04996.
OMAHNATVAM.
OrthoDBEOG7XPZ5K.
PhylomeDBP35561.
TreeFamTF313676.

Gene expression databases

BgeeP35561.
GenevestigatorP35561.

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

EvolutionaryTraceP35561.
NextBio289885.
PROP35561.
SOURCESearch...

Entry information

Entry nameIRK2_MOUSE
AccessionPrimary (citable) accession number: P35561
Entry history
Integrated into UniProtKB/Swiss-Prot: June 1, 1994
Last sequence update: June 1, 1994
Last modified: April 16, 2014
This is version 134 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

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

MGD cross-references

Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot