PRKN and Parkinson disease: The role of dysfunctional mitochondria in the pathogenesis of PD has been demonstrated in several models, including aging yeast (Buttner et al., 2008), Drosophila (Greene et al., 2003), as well as in Parkin-deficient transgenic mouse models (Palacino et al., 2004; Shim et al., 2011).