Structural basis of ion permeation gating in Slo2.1 K+ channels.

ABSTRACT: The activation gate of ion channels controls the transmembrane flux of permeant ions. In voltage-gated K(+) channels, the aperture formed by the S6 bundle crossing can widen to open or narrow to close the ion permeation pathway, whereas the selectivity filter gates ion flux in cyclic-nucleotide gated (CNG) and Slo1 channels. Here we explore the structural basis of the activation gate for Slo2.1, a weakly voltage-dependent K(+) channel that is activated by intracellular Na(+) and Cl(-). Slo2.1 channels were heterologously expressed in Xenopus laevis oocytes and activated by elevated [NaCl]i or extracellular application of niflumic acid. In contrast to other voltage-gated channels, Slo2.1 was blocked by verapamil in an activation-independent manner, implying that the S6 bundle crossing does

SUBMITTER: Garg P 

PROVIDER: S-EPMC3813382 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature