(A) ADP and dimerization mutants localize to mitochondria but are defective for mitochondrial fission. Wild-type MEFs were transfected with empty vector or MiD51-Myc constructs and treated with antimycin A. NM, nucleotide-binding site mutant (S189A); DM, compound dimer mutant.
(B) Quantification of results in (A). Mitochondrial morphologies were scored as described previously (Losón et al., 2013).
(C) Mitochondrial morphology in Fis1/Mff null MEFs transfected with empty vector or MiD51-Myc and treated with vehicle (DMSO) or antimycin A. Transfected cells were visualized with anti-Myc immunofluorescence, and mitochondria were highlighted with anti-Tom20 immunofluorescence.
(D) Quantification of results in (C).
In (B) and (D), data are averages from three independent experiments ±SD. Mitochondrial morphology scoring: S, short; L, long; N, net-like; C, collapsed. Scale bars, 10 µm. Regions within the white boxes are shown in greater magnification below.