Inward Rectifier Potassium Channel 4 (KCNJ4) Human Recombinant Protein

Several different potassium channels are known to be involved with electrical signaling in the nervous system. One class is activated by depolarization whereas a second class is not. The latter are referred to as inwardly rectifying K+ channels, and they have a greater tendency to allow potassium to flow into the cell rather than out of it. This asymmetry in potassium ion conductance plays a key role in the excitability of muscle cells and neurons. The protein encoded by this gene is an integral membrane protein and member of the inward rectifier potassium channel family. The encoded protein has a small unitary conductance compared to other members of this protein family. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

HIR: This receptor 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 extracellular barium and cesium. Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ4 subfamily.

Protein type: Membrane protein, multi-pass; Membrane protein, integral; Channel, potassium

Chromosomal Location of Human Ortholog: 22q13.1

Cellular Component: postsynaptic membrane; voltage-gated potassium channel complex; cytoplasmic vesicle membrane; basolateral plasma membrane; plasma membrane; cell junction

Molecular Function: protein binding; inward rectifier potassium channel activity; PDZ domain binding

Biological Process: synaptic transmission; potassium ion import; potassium ion transport