Distinct classes of potassium channels fused to GPCRs as electrical signaling biosensors

Abstract

Summary Ligand-gated ion channels (LGICs) are natural biosensors generating electrical signals in response to the binding of specific ligands. Creating de novo LGICs for biosensing applications is technically challenging. We have previously designed modified LGICs by linking G protein-coupled receptors (GPCRs) to the Kir6.2 channel. In this article, we extrapolate these design concepts to other channels with different structures and oligomeric states, namely a tetrameric viral Kcv channel and the dimeric mouse TREK-1 channel. After precise engineering of the linker regions, the two ion channels were successfully regulated by a GPCR fused to their N-terminal domain. Two-electrode voltage-clamp recordings showed that Kcv and mTREK-1 fusions were inhibited and activated by GPCR agonists, respectively, and antagonists abolished both effects. Thus, dissimilar ion channels can be allosterically regulated through their N-terminal domains, suggesting that this is a generalizable approach for ion channel engineering.

Photodynamic Activation of the Cholecystokinin 1 Receptor with Tagged Genetically Encoded Protein Photosensitizers: Optimizing the Tagging Patterns

“…3m). It might be worthwhile to investigate the theoretical basis, in the future, of the effect of varied linker length on the transduction of conformation changes between functional proteins, as reported also between GPCR and potassium channels (82). Nonetheless, we have in this work explored and optimized the fusion patterns of miniSOG and CCK1R for miniSOG photogenetical activation of in-frame CCK1R, which should be readily applicable to other GEPP, which have demonstrated as free-standing GEPP PM to photodynamically activate the endogenous CCK1R in AR4-2J cells (55).…”