KCNJ5

G protein-activated inward rectifier potassium channel 4 (GIRK-4) is a protein that in humans is encoded by the KCNJ5 gene and is a type of G protein-gated ion channel.^[5][6]

KCNJ5
Identifiers
Aliases	KCNJ5, CIR, GIRK4, KATP1, KIR3.4, LQT13, potassium voltage-gated channel subfamily J member 5, potassium inwardly rectifying channel subfamily J member 5
External IDs	OMIM: 600734; MGI: 104755; HomoloGene: 20248; GeneCards: KCNJ5; OMA:KCNJ5 - orthologs
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11q24.3 Start 128,891,356 bp[1] End 128,921,163 bp[1]
Gene location (Mouse) Chr. Chromosome 9 (mouse)[2] Band 9 A4|9 17.65 cM Start 32,226,003 bp[2] End 32,255,646 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in buccal mucosa cell endothelial cell adrenal cortex right adrenal gland left adrenal gland left adrenal cortex right adrenal cortex tendon of biceps brachii right ventricle myocardium Top expressed in atrium atrioventricular valve aortic valve olfactory epithelium endocardial cushion right lobe of liver myocardium of ventricle supraoptic nucleus right ventricle embryo More reference expression data BioGPS n/a
Gene ontology Molecular function G-protein activated inward rectifier potassium channel activity protein binding inward rectifier potassium channel activity voltage-gated ion channel activity voltage-gated potassium channel activity involved in atrial cardiac muscle cell action potential repolarization voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential repolarization Cellular component integral component of membrane T-tubule plasma membrane membrane external side of plasma membrane voltage-gated potassium channel complex Biological process potassium ion transport regulation of ion transmembrane transport ion transport regulation of heart rate by cardiac conduction membrane repolarization during atrial cardiac muscle cell action potential membrane repolarization during ventricular cardiac muscle cell action potential ventricular cardiac muscle cell membrane repolarization potassium ion import across plasma membrane Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3762 16521 Ensembl ENSG00000120457 ENSMUSG00000032034 UniProt P48544 P48545 RefSeq (mRNA) NM_000890 NM_001354169 NM_010605 RefSeq (protein) NP_000881 NP_001341098 NP_034735 Location (UCSC) Chr 11: 128.89 – 128.92 Mb Chr 9: 32.23 – 32.26 Mb PubMed search [3] [4]
Wikidata
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Function

Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and an inward-rectifier type potassium channel. The encoded protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, is controlled by G-proteins. It may associate with other G-protein-activated potassium channel subunits to form a heterotetrameric pore-forming complex.^[6]

In humans KCNJ5 is mainly expressed in the adrenal gland and pituitary, although it is also detected at low levels in the pancreas, spleen, lung, heart and brain.^[7] Consistent with this expression pattern, mutations in KCNJ5/Kir3.4 can cause familial hyperaldosteronism type III and a type of long QT syndrome.^[8]

Interactions

KCNJ5 has been shown to interact with KCNJ3.^[9][10]

See also

• G protein-coupled inwardly-rectifying potassium channel
• Inward-rectifier potassium ion channel