Two-pore domain potassium channel subfamily K member 3 (TASK-3) (KCNK3)

The two-pore domain potassium channel subfamily K member 3, commonly known as TASK-3 or KCNK3, is a leak potassium channel that sets the resting membrane potential in neurons and other cells by increasing potassium permeability, thereby hyperpolarizing the membrane and modulating excitability. It belongs to the K2P family of two-pore domain channels, which exhibit outward rectification and are active across a wide range of membrane potentials without voltage-gating or inactivation. TASK-3 is highly expressed in cerebellar granule neurons, hippocampus, thalamus, and other brain regions, where it supports sustained high-frequency action potential firing by reducing sodium channel inactivation and enhancing input conductance during depolarization. In TASK-3 knockout models, neurons show depolarized resting potentials, reduced leak conductance, and pronounced action potential accommodation, leading to firing failure during sustained stimuli. It forms homodimers or heterodimers with TASK-1, contributing to baseline potassium currents sensitive to pH and other modulators. While not directly linked to specific diseases in the sources, TASK-3 influences neuronal excitability relevant to processes like anesthesia response, as K2P channels including TASK-3 mediate hypnosis and immobilization effects. No approved drugs directly target TASK-3, but its role in background conductance positions it as a potential modulator of neuronal hyperactivity or related disorders.

Other names

TASK-3K2P3.1