Kcnj6
Function
This potassium channel is controlled by G proteins. It plays a role in granule cell differentiation, possibly via membrane hyperpolarization. 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.
Involvement in disease
Defects in Kcnj6 are the cause of the weaver (wv) phenotype. Homozygous animals suffer from severe ataxia that is obvious by about the second postnatal week. The cerebellum of these animals is drastically reduced in size due to depletion of the major cell type of cerebellum, the granule cell neuron. Heterozygous animals are not ataxic but have an intermediate number of surviving granule cells. Male homozygotes are sterile, because of complete failure of sperm production. Both hetero- and homozygous animals undergo sporadic tonic-clonic seizures.
Sequence Similarities
Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ6 subfamily.
Tissue Specificity
Cerebellum, testes, cortex and substentia nigra.
Cellular localization
- Membrane
- Multi-pass membrane protein
Alternative names
Girk2, Kcnj7, W, Kcnj6, G protein-activated inward rectifier potassium channel 2, GIRK-2, Inward rectifier K(+) channel Kir3.2