inward rectifier K+ channel 18; K+ channel, inwardly rectifying subfamily J member 18; Inward rectifier K+ channel Kir2.6 (KCNJ18)

Function

• inward-rectifier K+ channels are characterized by a greater tendency to allow K+ to flow into the cell rather than out of it
• their voltage dependence is regulated by the concentration of extracellular K+; as external K+ 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 Mg+2
• probably phosphorylated by PKC; decreases single-channel open probability

Structure

• belongs to the inward rectifier-type K+ channel (TC 1.A.2.1) family, KCNJ12 subfamily

Compartment

• cell membrane; multi-pass membrane protein (probable)

Expression

• specifically expressed in skeletal muscle
• up-regulated by triiodothyronine

Pathology

• defects in KCNJ18 are a cause of susceptibility to thyrotoxic hypokalemic periodic paralysis

More general terms

• inwardly-rectifying K+ channel subfamily J

Database

• OMIM: https://mirror.omim.org/entry/613236
• OMIM: https://mirror.omim.org/entry/613239
• UniProt: http://www.uniprot.org/uniprot/B7U540.html