Kir4.1 | Potassium Voltage-Gated Channel Subfamily J Member 10
Family:
Inward-rectifier potassium ion channel
Subgroups:
Seven families channels demonstrate robust inward rectification: Kir1.1; Kir2.1 - Kir2.4; Kir3.1 - Kir3.4, Kir4.1 - Kir4.2; Kir5.1, Kir6.1 - Kir6.2; Kir7.1
Topology:
The channel protein contains two membrane spanning alpha helices denoted as M1 and M2. Four identical subunits form a functional homotetramer, heterotetramers can combine with members of the same subfamily
Kir4.1 Background Information
Kir4.1 is an ATP-dependent inwardly rectifying potassium channel. It is expressed in the Stria vascularis and is essential for formation of the endolymph, the fluid that surrounds the mechanosensitive stereocilia of the sensory hair cells that make hearing possible. In the kidney, together with Kir5.1, the channel mediates basolateral K+ recycling in distal tubules; this process is critical for Na+ reabsorption at the tubules.
Gene:
KCNJ10
Human Protein:
UniProt P78508
Tissue:
Brain (astrocytes), kidney, inner ear, CD8 T cells
Function/ Application:
Responsible for the potassium buffering action of glial cells in the brain, mediates basolateral K+ recycling in distal tubules
Pathology:
Epilepsy, Ataxia, Sensorineural deafness, Tubulopathy, EAST syndrome (Gitelman syndrome phenotype), seizures, sensorineural deafness, mental retardation, and electrolyte imbalance (SESAMES)
Interaction:
Forms heteromers with Kir5.1, Kir4.2 and Kir2.1. It interacts with interleukin 16, MAGI1, PATJ, DLG1, DLG4, Gamma-aminobutyric acid B receptor 2
Modulator:
Barium chloride, Cesium chloride, Tertiopin-Q, Nortriptyline, Tolbutamide
Assays:
Patch clamp
Recommended Reviews:
Kubo et al. (2005) International Union of Pharmacology. LIV. Nomenclature and Molecular Relationships of Inwardly Rectifying Potassium Channels. Pharmacol Rev 57(4):509-526