GIRK4 This potassium channel is controlled by G proteins. 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 external barium. Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ5 subfamily. Islets, exocrine pancreas and heart. Expressed in the adrenal cortex, particularly the zona glomerulosa. Note: This description may include information from UniProtKB.
Protein type: Channel, potassium; Membrane protein, integral; Membrane protein, multi-pass
Chromosomal Location of Human Ortholog: 11q24.3
Cellular Component:  external side of plasma membrane; plasma membrane; T-tubule; voltage-gated potassium channel complex
Molecular Function:  G-protein activated inward rectifier potassium channel activity; protein binding; 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
Biological Process:  membrane repolarization during atrial cardiac muscle cell action potential; membrane repolarization during ventricular cardiac muscle cell action potential; potassium ion import across plasma membrane; potassium ion transport; regulation of heart rate by cardiac conduction; regulation of ion transmembrane transport; ventricular cardiac muscle cell membrane repolarization
Disease: Hyperaldosteronism, Familial, Type Iii; Long Qt Syndrome 13
Reference #:  P48544 (UniProtKB)
Alt. Names/Synonyms: cardiac ATP-sensitive potassium channel; Cardiac inward rectifier; CIR; G protein-activated inward rectifier potassium channel 4; G protein-activated inward rectifier potassium channel 4 (GIRK4) (Potassium channel, inwardly rectifying, subfamily J, member 5) (Inward rectifier K+ channel Kir3.4) (Heart KATP channel) (KATP-1) (Cardiac inward rectifier) (CIR)...; GIRK-4; GIRK4; Heart KATP channel; Inward rectifier K(+) channel Kir3.4; inward rectifier K+ channel KIR3.4; IRK-4; IRK5; KATP-1; KATP1; KCNJ5; KIR3.4; Potassium channel, inwardly rectifying subfamily J member 5; potassium inwardly-rectifying channel J5; potassium inwardly-rectifying channel, subfamily J, member 5
Gene Symbols: KCNJ5
Molecular weight: 47,668 Da
Basal Isoelectric point: 5.24  Predict pI for various phosphorylation states
Select Structure to View Below


Protein Structure Not Found.

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