Potassium channel subfamily K member 9 (TASK-3) (TASK-3)

Potassium channel subfamily K member 9 (TASK-3) is a pH-sensitive, two-pore domain potassium (K2P) channel that contributes to the background leak current, thereby regulating the resting membrane potential and cellular excitability (UniProt Q9NPC2). It is predominantly expressed in the central nervous system, particularly in the cerebellum and thalamus, as well as in the adrenal cortex (PubMed: 11091877). TASK-3 is characterized by its sensitivity to extracellular acidification, which inhibits the channel, and its activation by volatile anesthetics like halothane (PubMed: 10864915). In oncology, TASK-3 is recognized as a proto-oncogene, with its gene (KCNK9) frequently amplified or overexpressed in breast, lung, and colon cancers, promoting tumor growth and resistance to hypoxia (PubMed: 12871971). Furthermore, a specific gain-of-function mutation (p.Gly236Arg) in KCNK9 causes Birk-Barel syndrome, a genomic imprinting disorder characterized by intellectual disability and hypotonia (PubMed: 18678291). Consequently, TASK-3 is a target for small-molecule inhibitors in cancer therapy and potential activators for neurological disorders.

Other names

KCNK9TASK3K2P9.1Acid-sensitive potassium channel protein 2Two pore potassium channel KT3.1

Modulation of potassium leak currents to control membrane potential and cellular excitability.