Fig. 5. Mislocalization of membrane TRH receptor in cells expressing mutant GH and reversal with tunicamycin treatment. Cells cotransfected with wt-GH or 32-71-GH and HA-epitope-tagged TRH receptor were stained with antibody to the HA epitope (left panels) and antibody to GH (middle panels). Right panels show GH in red and HA in green; colocalized staining appears yellow. Approximately 80% of cells were positive for TRH receptor and 32% for GH. TRH receptor is localized on the plasma membrane in cells expressing wt-GH but retained in the ER in cells expressing the GH mutant. In cells expressing the GH mutant and treated with 10 µg/ml tunicamycin, plasma membrane localization of TRH receptor was restored in 45% of cells (bottom panels). TRHR, TRH receptor.