Two-P Potassium Channels

Two-P potassium channels (K_2P) are a family of proteins responsible for background potassium currents, which are important in stabilizing membrane potential. K_2Ps are so called because each subunit contains four transmembrane and two pore domains (P loops), although they do not form two pores; it is this 4TM/2P formation that characterizes the members of the K_2P channel family. They are thought to form functional dimers within the membrane. Fifteen K_2P channels have been identified to date, encoded by KCNK genes. These have been grouped into six subfamilies, TWIK, TREK, TASK, TALK, THIK, and TRESK, based on structural and functional properties.

K_2P channels are expressed in the kidney, brain, lung, heart, adrenal cortex and in the auditory and vestibular sensory systems, as well as in smooth muscle cells of the gut, bladder, uterus and vasculature. Under physiological conditions (high intracellular and low extracellular K⁺ concentration) the potassium current through the K_2P channel is predominantly outward. Activity of these channels is regulated by oxygen tension, pH, lipids, temperature, mechanical stretch, neurotransmitters and G protein-coupled receptors. They are considered to have a role in neural development, neuroprotection, pain signal processing and cardioprotection, among numerous other functions. K_2Ps are the target for some general and local anesthetics.

External sources of pharmacological information for Two-P Potassium Channels :

• IUPHAR Receptor Code

Two-P potassium channel Gene Data