Fig. 5.

Murine Mct8^L223R replicates the translocation defect found for human MCT8^L291R. a Transport activity of Mct8^L223R-MDCK1 cells treated with or without 4 mM NaPB compared to wild-type Mct8. The cells were incubated with 2 nM ¹²⁵I-T₃ and 10 nM T₃ for 20 min. Treated and untreated mock-transfected MDCK1 cells served as negative controls and were subtracted as background. n = 3. Statistics: Two-way ANOVA with Tukey's correction for multiple comparisons was used to compare treated with untreated wild-type Mct8 and Mct8^L223R. ^####p < 0.0001. In addition, untreated wild-type Mct8 was compared with untreated and treated Mct8^L223R. ****p < 0.0001. b Twenty micrograms of whole cell homogenates (left panel) and 30 µL of biotinylated protein (right panel) from treated and untreated MDCK1 cells stably expressing wild-type Mct8 and Mct8^L223R were analyzed by Western blotting. Mct8 was detected by anti-HA antibody. Beta-actin served as loading control. c Quantification of three Western blot analyses showing that murine Mct8^L223R replicates the translocation defect found for human MCT8^L291R. NaPB rescued the plasma membrane expression of mutant Mct8^L223R. Values are given as ±SD. The signal for actin was used for normalization. Statistical analyses: Two-way ANOVA with Dunnett's correction for multiple comparisons. Comparison of untreated Mct8^WT (darkest bars) with every other sample. *p < 0.05, **p < 0.01. d Immunohistochemical staining of Mct8^WT and untreated and NaPB-treated Mct8^L223R. Anti-HA antibody was used to detect Mct8 expression. Scale bar, 50 µm. HA, hemagglutinin; MCT8, monocarboxylate transporter 8; MDCK1, Madin-Darby canine kidney; NaPB, sodium phenylbutyrate; SD, standard deviation; T₃, 3,3′,5-triiodothyronine.