Fig. 4

GSK650394, a specific inhibitor of SGK1, reduces monensin-induced increase of mitochondrial MnSOD and Tom20 protein abundance, and catalase and ouabain blunt the effect of monensin on the mitochondrial Tom20 protein abundance in HEK293 cells. a GSK650394 significantly inhibits the effect of monensin on the mitochondrial MnSOD protein abundance. The subconfluent cells as described in Fig. 2a legend were pre-incubated with 0.1% DMSO or 2 μM GSK650394 for 45 min before 0.1% ethanol (control) or 10 μM monensin was added for additional 24 h (^#p < 0.01 vs the mito EtOH group, *p < 0.05 vs the mito monensin group, n = 7, two-way ANOVA). b GSK650394 significantly inhibits monensin-induced increase of mitochondrial Tom20 protein abundance. The HEK293 cells were treated in same way as in a. (^#p < 0.01 vs the mito EtOH group, *p < 0.05 vs the mito monensin group, n = 7, two-way ANOVA). c, d Both catalase (400 U/ml) and ouabain (4 nM) attenuate monensin-induced increase of mitochondrial Tom20 protein abundance. The cells were treated in the same way as in Fig. 3b, c. (^#p < 0.01 vs the mito EtOH group, *p < 0.05 vs the mito monensin group, in c, n = 11; in d, n = 10, two-way ANOVA for both)