Parkinson's disease-linked mutations in VPS35 induce dopaminergic neurodegeneration.
Bottom Line: The common D620N missense mutation in VPS35 does not compromise its protein stability or localization to endosomal and lysosomal vesicles, or the vesicular sorting of the retromer cargo, sortilin, SorLA and cation-independent mannose 6-phosphate receptor, in rodent primary neurons or patient-derived human fibroblasts.In yeast we show that PD-linked VPS35 mutations are functional and can normally complement VPS35 phenotypes suggesting that they do not result in a loss-of-function.Collectively, these studies establish that dominant VPS35 mutations lead to neurodegeneration in PD consistent with a gain-of-function mechanism, and support a key role for VPS35 in the development of PD.
Affiliation: Laboratory of Molecular Neurodegenerative Research.Show MeSH
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Mentions: To explore the putative pathogenic effects of dominant familial PD mutations in VPS35, we generated lentiviral vectors expressing V5-tagged human VPS35 harboring the common D620N mutation or wild-type (WT) protein. The D620N mutation does not influence the steady-state levels of human VPS35 protein exogenously expressed in rat primary cortical neurons (Fig. 2A). Furthermore, the D620N mutation fails to significantly alter the vesicular localization of human VPS35 (Fig. 2B–C). WT and D620N variants of VPS35 display a similar degree of co-localization with multiple vesicular or membranous compartments, including early (Rab5), late (Rab7) and recycling (Rab9) endosomes, lysosomes (LAMP1) and the trans-Golgi network (Giantin/GOLGB1 and Golgin/GOLGA4) in primary cortical neurons (Fig. 2B–C). We do not observe any clear differences in the subcellular distribution of VPS35-positive endosomal and lysosomal vesicles between the WT and D620N variants (Fig. 2B). In general, the D620N mutation does not compromise the protein stability or vesicular localization of VPS35.Figure 2.
Affiliation: Laboratory of Molecular Neurodegenerative Research.