The Lipid Activation Mechanism of a Transmembrane Potassium Channel.

ABSTRACT: Membrane proteins and lipids coevolved to yield unique coregulatory mechanisms. Inward-rectifier K⁺ (Kir) channels are often activated by anionic lipids endemic to their native membranes and require accessible water along their K⁺ conductance pathway. To better understand Kir channel activation, we target multiple mutants of the Kir channel KirBac1.1 via solid-state nuclear magnetic resonance (SSNMR) spectroscopy, potassium efflux assays, and Förster resonance energy transfer (FRET) measurements. In the I131C stability mutant (SM), we observe an open-active channel in the presence of anionic lipids with greater activity upon addition of cardiolipin (CL). The introduction of three R to Q mutations (R49/151/153Q (triple Q mutant, TQ)) renders the protein inactive within

SUBMITTER: Borcik CG 

PROVIDER: S-EPMC8281327 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature