Research Paper Volume 9, Issue 10 pp 2163—2189

SIRT4 interacts with OPA1 and regulates mitochondrial quality control and mitophagy

Figure 6. SIRT4-eGFP expression stabilizes the mitochondrial fusion regulator L-OPA1. (A) The expression of L-OPA1 vs. S-OPA1 was analyzed by immunoblotting in HEK293 cells stably expressing eGFP, SIRT4-eGFP, SIRT4(H161Y)-eGFP, or SIRT4(Δ28N)-eGFP. As a control for complete proteolytic processing of L-OPA1 to S-OPA1 eGFP-expressing control cells were treated with CCCP (10 µM) for two hours. (B) The ratio between the expression levels of L-OPA1 and S-OPA1 was determined by ImageJ-based densitometric analysis. To evaluate statistical significance (compared to eGFP), two-way ANOVA followed by Tukey’s tests was performed (**p<0.01; n=6).