Potassium channel subfamily K member 9 (IPR005407)

Short name: KCNK9

Overlapping homologous superfamilies


Family relationships


TASK is a member of the TWIK-related (two P-domain) K+ channel family identified in human tissues [PMID: 9312005]. It is widely distributed, being particularly abundant in the pancreas and placenta, but it is also found in the brain, heart, lung and kidney. Its amino acid identity to TWIK-1 and TREK-1 is rather low, being about 25-28%. However, it is thought to share the same topology of four TM segments, with two P-domains. TASK is very sensitive to variations in extracellular pH in the physiological range, changing from fully-open to closed in approximately 0.5 pH units around pH 7.4. Thus, it may well be a biological sensor of external pH variations.

Potassium channel subfamily K member 9 (KCNK9, also known as TASK3) is a pH-dependent, voltage-insensitive, background potassium channel protein [PMID: 11042359, PMID: 11431495].

GO terms

Biological Process

GO:0071805 potassium ion transmembrane transport

Molecular Function

GO:0005267 potassium channel activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.