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 V-2 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 V(2)Rs 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. (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.