The mechano-gated K2P channel TREK-1

The versatility of neuronal electrical activity is largely conditioned by the expression of different structural and functional classes of K⁺ channels. More than 80 genes encoding the main K⁺ channel alpha subunits have been identified in the human genome. Alternative splicing, heteromultimeric assembly, post-translational modification and interaction with auxiliary regulatory subunits further increase the molecular and functional diversity of K⁺ channels. Mammalian two-pore domain K⁺ channels (K_2P) make up one class of K⁺ channels along with the inward rectifiers and the voltage- and/or calcium-dependent K⁺ channels. Each K_2P channel subunit is made up of four transmembrane segments and two pore-forming (P) domains, which are arranged in tandem and function as either homo- or heterodimeric channels. This novel structural arrangement is associated with unusual gating properties including “background” or “leak” K⁺ channel activity, in which the channels show constitutive activity at rest. In this review article, we will focus on the lipid-sensitive mechano-gated K_2P channel TREK-1 and will emphasize on the polymodal function of this “unconventional” K⁺ channel. EBSA Satellite meeting: Ion channels, Leeds, July 2007.