Fig. 6. Effect of ceramide on HERG channel ubiquitylation and degradation in HEK cells. As shown in this study, ceramide leads to HERG channel ubiquitylation and subsequent degradation via lysosomes. However, ceramide also inhibits to some extent the basal turnover of HERG protein through proteosomes. Bafilomycin is a lysosome inhibitor whereas MG132 and lactacystin inhibit proteosomal degradation. See Discussion for further details.