Ball-and-chain inactivation in a calcium-gated potassium channel.

ABSTRACT: Inactivation is the process by which ion channels terminate ion flux through their pores while the opening stimulus is still present¹. In neurons, inactivation of both sodium and potassium channels is crucial for the generation of action potentials and regulation of firing frequency^1,2. A cytoplasmic domain of either the channel or an accessory subunit is thought to plug the open pore to inactivate the channel via a 'ball-and-chain' mechanism^3-7. Here we use cryo-electron microscopy to identify the molecular gating mechanism in calcium-activated potassium channels by obtaining structures of the MthK channel from Methanobacterium thermoautotrophicum-a purely calcium-gated and inactivating channel-in a lipid environment. In the absence of Ca²⁺, we

SUBMITTER: Fan C 

PROVIDER: S-EPMC7153497 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature