FIGURE 5.

Role of hVps24 in hERG degradation. A, hERG expression levels in control (Ctl) or hVps24-transfected hERG-HEK cells cultured in 5 or 0 mm K⁺ MEM for 4 h (n = 5). Thirty-six hours after transfection, cell culture medium was changed to 5 or 0 mm K⁺ MEM for 4 h, and analysis was performed. Expression of hVps24 was detected with an anti-Myc antibody. B, I_hERG in control (Ctl) or hVps24-transfected hERG-HEK cells cultured in 5 or 0 mm K⁺ MEM for 2 h. The averaged tail currents are shown in the lower panel. C, hERG expression levels in hERG-HEK cells transfected with control siRNA (Ctl) or hVps24 siRNA after 6-h culture in 5 or 0 mm K⁺ MEM (n = 3). Forty-eight hours after transfection, the culture medium was changed to 5 or 0 mm K⁺ MEM, and cells were cultured for 6 h and then collected for analysis. D, I_hERG in hERG-HEK cells transfected with control siRNA (Ctl) or hVps24 siRNA after 6-h culture in 5 or 0 mm K⁺ MEM. The averaged tail currents are shown in the lower panel. The numbers in parentheses shown above the histograms in B and D indicate the number of cells tested. In B and D, Error bars represent standard error of the mean. ** denotes p < 0.01 compared with the respective controls.