Figure 7.

Fusion-competent, CMT2A-associated MFN2 mutants cannot compensate for the mitochondrial transport abnormality in Mfn2^−/− neurons. To compare the ability of fusion-competent (L76P, W740S) and fusion-incompetent (R94Q) MFN2 mutants to mediate mitochondrial transport, we reintroduced these mutants into Mfn2^−/− neurons and assessed their ability to rescue the mitochondrial transport abnormality. As compared with wtMFN2, neither the fusion-competent (L76P, W740S) nor fusion-incompetent (R94Q) mutants were able to fully restore mitochondrial pause time (A, B) (n is number of axons from which kymographs were generated) or mitochondrial velocities (C).