G Protein Coupled Receptor 89B (GPR89B)

The deduced 455-amino acid human protein shares 96% and 92% amino acid identity with the respective mouse and Xenopus proteins. Immunoelectron microscopy and subcellular fractionation indicated that the majority of endogenous GPHR was localized to the Golgi. Western blot analysis and SDS-PAGE indicated that the GPHR channel was composed of trimeric GPHR, consistent with the presence of multiple substates of conductance.In vitro reconstitution of GPR89B in an artificial lipid bilayer expressed in Sf9 insect cells and additional studies in semi-intact C27 cells showed that GPR89B displayed voltage-dependent anion channel activity that was selective for I-, Cl-, Br-, and F- ions, in that order of selectivity. Activity was inhibited by anion channel inhibitor DIDS (4,4-prime-diisothiocyanatostilbene-2,2-prime-disulfonic acid).