Structural Foundations of Potassium Selectivity in Channelrhodopsins.

ABSTRACT: Potassium-selective channelrhodopsins (KCRs) are light-gated K⁺ channels recently found in the stramenopile protist Hyphochytrium catenoides. When expressed in neurons, KCRs enable high-precision optical inhibition of spiking (optogenetic silencing). KCRs are capable of discriminating K⁺ from Na⁺ without the conventional K⁺ selectivity filter found in classical K⁺ channels. The genome of H. catenoides also encodes a third paralog that is more permeable for Na⁺ than for K⁺. To identify structural motifs responsible for the unusual K⁺ selectivity of KCRs, we systematically analyzed a series of chimeras and mutants of this protein. We found that mutations of three critical residues in the paralog convert i

SUBMITTER: Govorunova EG 

PROVIDER: S-EPMC9765531 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature