Potassium Channel Subfamily K, Member 1 (KCNK1)

KCNK1 has not been shown to be a functional channel, however, and it may require other non-pore-forming proteins for activity.A cDNA, designated TWIK1 by the authors, was obtained from a human kidney library and shown to encode a predicted 336-amino acid protein. Unlike other potassium channels, TWIK1 has 4 (rather than 6) transmembrane domains and 2 (rather than 1) P domains. Two genes from C. elegans are related. When expressed in Xenopus oocytes, TWIK1 is able to direct expression of weakly inward-rectifying potassium currents. Northern blots showed that the gene is transcribed in a large number of tissues but is especially highly expressed in the brain and heart. The authors speculated that TWIK1 channels may be involved in the control of background potassium membrane conductances.