Figure 6.

Agonist-promoted TAS2R14 internalization and sorting to early endosomes is altered by Ser/Thr mutations.A, representative experiment showing agonist (DPD)-promoted loss of cell surface receptors as determined by Western blotting of the membrane fraction. B, mean ± SD, and individual results, from four cell surface expression experiments. ∗p < 0.05 versus WT. C, agonist-promoted colocalization (yellow signal) of WT receptor with the early endosome marker EEA1, which was not observed with any of the indicated mutant TAS2R14 receptors. Shown is a representative experiment. The scale bars are shown in the bottom right-hand panel for each cell line. B, mean ± SD, and individual results, from four colocalization experiments. ∗p Value not significantly different compared with vehicle control. CT, carboxy-terminal tail; DAPI, 4′,6-diamidino-2-phenylindole; DPD, diphenhydramine; EEA1, early endosome antigen 1; IL, intracellular loop; TAS2R14, bitter taste 2 receptor member 14.