Structural basis and energy landscape for the Ca²⁺ gating and calmodulation of the Kv7.2 K⁺ channel.

ABSTRACT: The Kv7.2 (KCNQ2) channel is the principal molecular component of the slow voltage-gated, noninactivating K⁺ M-current, a key controller of neuronal excitability. To investigate the calmodulin (CaM)-mediated Ca²⁺ gating of the channel, we used NMR spectroscopy to structurally and dynamically describe the association of helices hA and hB of Kv7.2 with CaM, as a function of Ca²⁺ concentration. The structures of the CaM/Kv7.2-hAB complex at two different calcification states are reported here. In the presence of a basal cytosolic Ca²⁺ concentration (10-100 nM), only the N-lobe of CaM is Ca²⁺-loaded and the complex (representative of the open channel) exhibits collective dynamics on the millisecond time scale toward a low-pop

SUBMITTER: Bernardo-Seisdedos G 

PROVIDER: S-EPMC5873240 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature