Fig. 5
CD98hc determines the level of DES2 in fibroblasts. a–d Loss of CD98hc or expression of C330S mutant reduce the expression of DES2 and induces DES1. One experiment representative of at least n = 3 experiments. e–h Levels of DES1 and DES2 mRNA as measured by RT-qPCR on total mRNA from CD98hc-null cells or C330S reconstituted null cells. Means are plotted with s.e.m. as error bars from, respectively, n = 6 or n = 3 experiments. Differences were not statistically different in a Student’s t test. i Schematic representation of the de novo sphingolipid biosynthesis pathway presenting variations of metabolites. Numbers refer to metabolites depicted and numbered in the volcano plot of Fig. 4d. Metabolites and p values are reported in Supplementary Data 1. P values were calculated using a Student’s t test. DES1/2 variations were extracted from results presented in Fig. 5a–d and Supplementary Figure 5A–D. j, k Hsp90 inhibition in control cells reduces the level of DES2 expressed in cells. Right panel, means are plotted with s.e.m. as error bars from n = 3 experiments, **P < 0.01 in a Student’s t test. l Grp78 and Grp94 co-immunoprecipitate with DES2 upon loss of CD98hc or geldanamycin treatment. Control, CD98hc-null, or C330S-expressing cells were treated with geldanamycin for 16 h prior to cell lysis and DES2 immunoprecipitation. Precipitates were loaded on SDS–PAGE and analyzed by Western blot. One experiment representative of n = 2
