Potassium two pore domain channel subfamily K member 9 (KCNK9)

Potassium two pore domain channel subfamily K member 9 (KCNK9, also known as TASK3) is a pH-sensitive, two-pore domain potassium ion channel that contributes to “leak” potassium currents, helping to set membrane potential and regulate cellular excitability, especially in neurons. It is expressed most highly in the brain (notably cerebellum and hippocampus) but is present in various tissues including the adrenal gland and retina. KCNK9 is regulated by extracellular pH and signaling pathways involving G protein-coupled receptors, and is inhibited by various endogenous and pharmacologic molecules. Overexpression or amplification of KCNK9 has been identified in multiple human cancers, where it promotes proliferation and resistance to apoptosis, illustrating both physiological and pathological roles. Genetic variants of KCNK9 cause congenital imprinting syndromes. There are currently no approved drugs that specifically target KCNK9 clinically, but its modulation is a subject of active research for both neurologic and oncologic indications

Other names

TASK3TASK-3K2p9.1TWIK-related acid-sensitive K(+) channel 3Acid-sensitive potassium channel protein TASK-3Potassium channel subfamily K member 9Potassium channel, two pore domain subfamily K, member 9Two pore potassium channel KT3.2BIBARSTASK32KT3.2

Opening or closing the channel regulates potassium (K+) outflow, affecting membrane potential and cell excitability. Inhibition results in depolarization, altering neuronal signaling, hormone release, and potentially promoting or inhibiting tumorigenic processes. In oncogenesis, overexpression increases resistance to apoptosis and cell proliferation via alteration of membrane potential and downstream signaling pathways.