The bile acid-sensitive ion channel is gated by Ca²⁺-dependent conformational changes in the transmembrane domain.

ABSTRACT: The bile acid-sensitive ion channel (BASIC) is the least understood member of the mammalian epithelial Na⁺ channel/degenerin (ENaC/DEG) superfamily of ion channels, which are involved in a variety of physiological processes. While some members of this superfamily, including BASIC, are inhibited by extracellular Ca²⁺ (Ca²⁺ _o), the molecular mechanism underlying Ca²⁺ modulation remains unclear. Here, by determining the structure of human BASIC in the presence and absence of Ca²⁺ using single particle cryo-electron microscopy (cryo-EM), we reveal Ca²⁺-dependent conformational changes in the transmembrane domain and β-linkers. Electrophysiological experiments further show that a glutamate residue in the extracellular

SUBMITTER: Freitas MM 

PROVIDER: S-EPMC11741473 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature