Use of Kikume green–red fusions to study the influence of pharmacological chaperones on trafficking of G protein-coupled receptors

In this study we demonstrate that the photoconvertible monomeric Kikume green–red (mKikGR) protein is suitable to study trafficking of G protein-coupled receptors. Taking mKikGR-tagged mutants of the vasopressin V2 receptor (V2R) as models, we analyzed whether the V2R-specific pharmacological chaperone SR121463B influences receptor folding on a co- or post-translational level. Misfolded mKikGR-tagged V2Rs were completely photoconverted in the early secretory pathway yielding a red receptor population (already synthesized receptors) and an arising green receptor population (newly synthesized receptors). Trafficking of both receptor populations could be rescued by treatment with SR121463B demonstrating that the substance can act co- and post-translationally.

► We constructed fusions of the vasopressin V2 receptor with the photoconvertible mKikGR protein.
► We show that mKikGR fusions can be used to study receptor trafficking.
► Using mKikGR fusions, we show that pharmacological chaperones may act co- and post-translationally.