Aliases for KCNJ4 Gene
External Ids for KCNJ4 Gene
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]
GeneCards Summary for KCNJ4 Gene
KCNJ4 (Potassium Channel, Inwardly Rectifying Subfamily J, Member 4) is a Protein Coding gene. Among its related pathways are GABA receptor activation and Transmission across Chemical Synapses. GO annotations related to this gene include PDZ domain binding and inward rectifier potassium channel activity. An important paralog of this gene is KCNJ3.
UniProtKB/Swiss-Prot for KCNJ4 Gene
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 (By similarity).
The inward-rectifier potassium channel family (also known as 2-TM channels) include the strong inward-rectifier channels (KIR2.x), the G-protein-activated inward-rectifier channels (KIR3.x) and the ATP-sensitive channels (KIR6.x, which combine with sulphonylurea receptors (SUR)). Structurally, the pore-forming subunit of KIR channels is the alpha-subunit. It contains a single pore domain between two membrane spanning regions. Four alpha-subunits combine to form a tetramer, with the pore domain of each subunit contributing to the structure of the central pore. Heteromeric channels can also be formed within subfamilies, e.g. KIR3.2 with KIR3.3.