Potassium Channel Subfamily K, Member 3 (KCNK3)

KCNK3 encodes K_2P3.1, one of the members of the superfamily of potassium channel proteins containing two pore-forming P domains. K_2P3.1 is an outwardly rectifying channel that is sensitive to changes in extracellular pH and is inhibited by extracellular acidification. Also referred to as an acid-sensitive potassium channel, it is activated by the anesthetics halothane and isoflurane. The mouse cDNA was used to clone the human counterpart from a kidney cDNA library. The human cDNA, designated TASK, encodes a 394-amino acid polypeptide with 85% identity to the mouse ortholog. The sequence contains consensus sites for N-linked glycosylation and for phosphorylation at the C terminus. Northern blot analysis showed that TASK is expressed in a variety of human tissues, with highest levels in pancreas and placenta.