F) WT and Mfn2 KO MEFs were co-transfected with GFP and ERMITO-RLuc plasmids. After 24 h, the transfected cells were sorted and plated for another 24 h, after which RLuc was analyzed, the activity of which requires the proper apposition of the ER and mitochondria to reconstitute the split RLuc (n= 3 independent experiments). Data are presented as mean ± SEM. *p<0.05, two-tailed Student's t-test. 