Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Inward rectifier potassium channel 4

Gene

KCNJ4

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

Functioni

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)DescriptionActionsGraphical viewLength
Sitei164Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesiumBy similarity1

GO - Molecular functioni

  • G-protein activated inward rectifier potassium channel activity Source: Reactome
  • inward rectifier potassium channel activity Source: ProtInc
  • PDZ domain binding Source: UniProtKB

GO - Biological processi

  • potassium ion import Source: GO_Central
  • potassium ion transport Source: ProtInc
  • regulation of ion transmembrane transport Source: UniProtKB-KW

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

Names & Taxonomyi

Protein namesi
Recommended name:
Inward rectifier potassium channel 4
Alternative name(s):
HIRK2
HRK1
Hippocampal inward rectifier
Short name:
HIR
Inward rectifier K(+) channel Kir2.3
Short name:
IRK-3
Potassium channel, inwardly rectifying subfamily J member 4
Gene namesi
Name:KCNJ4
Synonyms:IRK3
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 22

Organism-specific databases

EuPathDBiHostDB:ENSG00000168135.4
HGNCiHGNC:6265 KCNJ4
MIMi600504 gene
neXtProtiNX_P48050

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 domaini1 – 55CytoplasmicBy similarityAdd BLAST55
Transmembranei56 – 80Helical; Name=M1By similarityAdd BLAST25
Topological domaini81 – 120ExtracellularBy similarityAdd BLAST40
Intramembranei121 – 132Helical; Pore-forming; Name=H5By similarityAdd BLAST12
Intramembranei133 – 139Pore-formingBy similarity7
Topological domaini140 – 148ExtracellularBy similarity9
Transmembranei149 – 170Helical; Name=M2By similarityAdd BLAST22
Topological domaini171 – 445CytoplasmicBy similarityAdd BLAST275

Keywords - Cellular componenti

Cell junction, Cell membrane, Cytoplasmic vesicle, Membrane, Postsynaptic cell membrane, Synapse

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi117H → E: Loss of pH-sensitivity. 1 Publication1

Organism-specific databases

DisGeNETi3761
OpenTargetsiENSG00000168135
PharmGKBiPA30048

Chemistry databases

ChEMBLiCHEMBL2146347
GuidetoPHARMACOLOGYi432

Polymorphism and mutation databases

BioMutaiKCNJ4
DMDMi1352483

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001549301 – 445Inward rectifier potassium channel 4Add BLAST445

Proteomic databases

PaxDbiP48050
PeptideAtlasiP48050
PRIDEiP48050
ProteomicsDBi55841

PTM databases

iPTMnetiP48050
PhosphoSitePlusiP48050

Expressioni

Tissue specificityi

Heart, skeletal muscle, and several different brain regions including the hippocampus.

Gene expression databases

BgeeiENSG00000168135
CleanExiHS_KCNJ4
ExpressionAtlasiP48050 baseline and differential
GenevisibleiP48050 HS

Interactioni

Subunit structurei

Homomultimeric and heteromultimeric association with KCNJ2 and KCNJ12. 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). Interacts with TAX1BP3. TAX1BP3 competes with LIN7 family members for KCNJ4 binding.By similarity2 Publications

GO - Molecular functioni

  • PDZ domain binding Source: UniProtKB

Protein-protein interaction databases

BioGridi109963, 10 interactors
ELMiP48050
IntActiP48050, 4 interactors
MINTiP48050
STRINGi9606.ENSP00000306497

Chemistry databases

BindingDBiP48050

Structurei

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3GJ9X-ray2.80C/D436-445[»]
ProteinModelPortaliP48050
SMRiP48050
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP48050

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni91 – 111Val/Gly/Ala/Pro stretchAdd BLAST21

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi134 – 139Selectivity filterBy similarity6
Motifi443 – 445PDZ-bindingSequence analysis3

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi102 – 105Poly-Gly4
Compositional biasi362 – 368Poly-Pro7
Compositional biasi383 – 390Poly-Glu8
Compositional biasi391 – 399Poly-Ala9

Domaini

The Val/Gly/Ala/Pro stretch may have a functional role in the conductance or permeation properties.

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG3827 Eukaryota
ENOG410XQ62 LUCA
GeneTreeiENSGT00760000118842
HOGENOMiHOG000237325
HOVERGENiHBG006178
InParanoidiP48050
KOiK04998
OMAiKSCPGLG
OrthoDBiEOG091G08HC
PhylomeDBiP48050
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
IPR003273 K_chnl_inward-rec_Kir2.3
IPR013518 K_chnl_inward-rec_Kir_cyto
PANTHERiPTHR11767 PTHR11767, 1 hit
PTHR11767:SF53 PTHR11767:SF53, 1 hit
PfamiView protein in Pfam
PF01007 IRK, 1 hit
PIRSFiPIRSF005465 GIRK_kir, 1 hit
PRINTSiPR01326 KIR23CHANNEL
PR01320 KIRCHANNEL
SUPFAMiSSF81296 SSF81296, 1 hit

Sequencei

Sequence statusi: Complete.

P48050-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MHGHSRNGQA HVPRRKRRNR FVKKNGQCNV YFANLSNKSQ RYMADIFTTC
60 70 80 90 100
VDTRWRYMLM IFSAAFLVSW LFFGLLFWCI AFFHGDLEAS PGVPAAGGPA
110 120 130 140 150
AGGGGAAPVA PKPCIMHVNG FLGAFLFSVE TQTTIGYGFR CVTEECPLAV
160 170 180 190 200
IAVVVQSIVG CVIDSFMIGT IMAKMARPKK RAQTLLFSHH AVISVRDGKL
210 220 230 240 250
CLMWRVGNLR KSHIVEAHVR AQLIKPYMTQ EGEYLPLDQR DLNVGYDIGL
260 270 280 290 300
DRIFLVSPII IVHEIDEDSP LYGMGKEELE SEDFEIVVIL EGMVEATAMT
310 320 330 340 350
TQARSSYLAS EILWGHRFEP VVFEEKSHYK VDYSRFHKTY EVAGTPCCSA
360 370 380 390 400
RELQESKITV LPAPPPPPSA FCYENELALM SQEEEEMEEE AAAAAAVAAG
410 420 430 440
LGLEAGSKEE AGIIRMLEFG SHLDLERMQA SLPLDNISYR RESAI
Length:445
Mass (Da):49,500
Last modified:February 1, 1996 - v1
Checksum:i893F03365273E8BE
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti16 – 17KR → NG in AAC60632 (PubMed:8051145).Curated2
Sequence conflicti107A → D in AAA66076 (PubMed:8034048).Curated1
Sequence conflicti350A → G in AAC60632 (PubMed:8051145).Curated1
Sequence conflicti392A → S in AAA66076 (PubMed:8034048).Curated1
Sequence conflicti395A → S in AAA66076 (PubMed:8034048).Curated1
Sequence conflicti396A → R (PubMed:8051145).Curated1
Sequence conflicti398A → G (PubMed:8051145).Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U07364 mRNA Translation: AAA19962.1
U24056 mRNA Translation: AAA66076.1
S72503 mRNA Translation: AAC60632.1
CR456507 mRNA Translation: CAG30393.1
Z97056 Genomic DNA No translation available.
BC113506 mRNA Translation: AAI13507.1
BC113508 mRNA Translation: AAI13509.1
CCDSiCCDS13971.1
PIRiA54852
I38521
RefSeqiNP_004972.1, NM_004981.1
NP_690607.1, NM_152868.2
UniGeneiHs.32505

Genome annotation databases

EnsembliENST00000303592; ENSP00000306497; ENSG00000168135
GeneIDi3761
KEGGihsa:3761
UCSCiuc003avt.3 human

Similar proteinsi

Entry informationi

Entry nameiKCNJ4_HUMAN
AccessioniPrimary (citable) accession number: P48050
Secondary accession number(s): Q14D44
Entry historyiIntegrated into UniProtKB/Swiss-Prot: February 1, 1996
Last sequence update: February 1, 1996
Last modified: June 20, 2018
This is version 170 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

3D-structure, Complete proteome, Reference proteome

Documents

  1. Human chromosome 22
    Human chromosome 22: entries, gene names and cross-references to MIM
  2. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  3. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  4. SIMILARITY comments
    Index of protein domains and families

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health