PRKN and Parkinson disease: Interestingly, Mfn is a substrate of the E3 ubiquitin ligase Parkin, mutated in Parkinson’s disease (PD) (Ziviani et al., 2010), and Parkin mutations associated with genetic forms of PD compromise the ability to ubiquitinate Mfn (Glauser et al., 2011), implying Mfns in the function of dopaminergic neurons and in pathogenesis of PD.