Channelopathy of small- and intermediate-conductance Ca²⁺-activated K⁺ channels.

ABSTRACT: Small- and intermediate-conductance Ca²⁺-activated K⁺ (K_Ca2.x/K_Ca3.1 also called SK/IK) channels are gated exclusively by intracellular Ca²⁺. The Ca²⁺ binding protein calmodulin confers sub-micromolar Ca²⁺ sensitivity to the channel-calmodulin complex. The calmodulin C-lobe is constitutively associated with the proximal C-terminus of the channel. Interactions between calmodulin N-lobe and the channel S4-S5 linker are Ca²⁺-dependent, which subsequently trigger conformational changes in the channel pore and open the gate. KCNN genes encode four subtypes, including KCNN1 for K_Ca2.1 (SK1), KCNN2 for K_Ca2.2 (SK2), KCNN3 for K_Ca2.3 (SK3), and KCNN4 for K_Ca3.1 (IK).

SUBMITTER: Nam YW 

PROVIDER: S-EPMC9889811 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature