Investigation Of The Physiological And Pathological Functions Of Arachidonic Acid-sensitive And Mechano-gated Tandem-pore-domain Potassium Channels TREK-1,TREK-2 And TRAAK

Tandem-pore-domain potassium channels (K_2P) constitute a multipal subfamily of potassium channels that have been recently elucidated. Their structure motif is quite different from classic potassium channels such as Kv and Kir with 4 transmembrane segments (M1-M4) and 2 pore domains (P1, P2): 4TMS/2P. Because of their similarity in sequences and regulation mechanisms, TREK-1, TREK-2 and TRAAK were divided into one type: arachidonic acid-sensitive and mechano-gated tandem-pore-domain potassium channels (TREK). Recent studies showed that they have specific expression in neurons in the central nervous system (CNS). Study has also showed that they are expressed in mouse and rat as well as in human.The current of TREK potassium channels shares the same characteristics of spontaneous, voltage- and time-dependent, non-inactivating. The most distinctive character of TREK potassium channels lies in their strong activation by polyunsaturated fatty acids such as arachidonic acid and also negative mechanical stretch, but not by saturated fatty acids. The other character is that they are not sensitive to classic potassium channel antagonists such as 4-AP, TEA and Cs⁺. In physiological conditions, they can produce the baseline or leak current in excitable cells and are involved in the determination of cellular excitability.The special structure, specific expression pattern and particular regulation mechanisms of TREK potassium channels indicated that they might have specially...