Structural bases for blockade and activation of BK channels by Ba²⁺ ions.

ABSTRACT: We studied the impact of Ba²⁺ ions on the function and structure of large conductance potassium (BK) channels. Ion composition has played a crucial role in the physiological studies of BK channels due to their ability to couple ion composition and membrane voltage signaling. Unlike Ca²⁺, which activates BK channels through all Regulator of K ⁺ Conductance (RCK) domains, Ba²⁺ has been described as specifically interacting with the RCK2 domain. It has been shown that Ba²⁺ also blocks potassium permeation by binding to the channel's selectivity filter. The Cryo-EM structure of the Aplysia BK channel in the presence of high concentration Ba²⁺ here presented (PDBID: 7RJT) revealed that Ba²⁺

SUBMITTER: Srivastava S 

PROVIDER: S-EPMC11445749 | biostudies-literature | 2024

REPOSITORIES: biostudies-literature