KCNJ12

This gene encodes an inwardly rectifying K+ channel which may be blocked by divalent cations. This protein is thought to be one of multiple inwardly rectifying channels which contribute to the cardiac inward rectifier current (IK1). The gene is located within the Smith-Magenis syndrome region on chromosome 17. [provided by RefSeq, Jul 2008]

Full Name

Potassium Voltage-Gated Channel Subfamily J Member 12

Function

Inward rectifying potassium channel that is activated by phosphatidylinositol 4,5-bisphosphate and that probably participates in controlling the resting membrane potential in electrically excitable cells. Probably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. 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.

Biological Process

Muscle contractionManual Assertion Based On ExperimentTAS:ProtInc
Potassium ion import across plasma membraneManual Assertion Based On ExperimentIBA:GO_Central
Potassium ion transportManual Assertion Based On ExperimentIDA:UniProtKB
Protein homotetramerizationManual Assertion Based On ExperimentIDA:UniProtKB
Regulation of heart contractionManual Assertion Based On ExperimentTAS:ProtInc
Regulation of ion transmembrane transportManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Cell membrane

Topology

Cytoplasmic: 1-82
Helical: 83-107
Extracellular: 108-123
Helical: 124-141
Pore-forming: 142-151
Extracellular: 152-156
Helical: 157-181
Cytoplasmic: 182-433