title: Aggregation of α-synuclein in S. cerevisiae is associated with defects in endosomal trafficking and phospholipid biosynthesis.
abstract: Parkinson's disease is the most common neurodegenerative movement disorder. α-Synuclein is a small synaptic protein that has been linked to familial Parkinson's disease (PD) and is also the primary component of Lewy bodies, the hallmark neuropathology found in the brain of sporadic and familial PD patients. The function of α-synuclein is currently unknown, although it has been implicated in the regulation of synaptic vesicle localization or fusion. Recently, overexpression of α-synuclein was shown to cause cytoplasmic vesicle accumulation in a yeast model of α-synuclein toxicity, but the exact role α-synuclein played in mediating this vesicle aggregation is unclear. Here, we show that α-synuclein induces aggregation of many yeast Rab GTPase proteins, that α-synuclein aggregation is enhanced in yeast mutants that produce high levels of acidic phospholipids, and that α-synuclein colocalizes with yeast membranes that are enriched for phosphatidic acid. Significantly, we demonstrate that α-synuclein expression induces vulnerability to perturbations of Ypt6 and other proteins involved in retrograde endosome-Golgi transport, linking a specific trafficking defect to α-synuclein phospholipid binding. These data suggest new pathogenic mechanisms for α-synuclein neurotoxicity.
authors.affiliation: Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. soper@mail.med.upenn.edu
authors.forename: James H
authors.initials: JH
authors.lastname: Soper
authors.forename: Victoria
authors.initials: V
authors.lastname: Kehm
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Burd
authors.forename: Vytas A
authors.initials: VA
authors.lastname: Bankaitis
authors.forename: Virginia M-Y
authors.initials: VM
authors.lastname: Lee
mesh_terms: D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D010743:Phospholipids / Q000096:biosynthesis*; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: D010743:Phospholipids; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D051844:alpha-Synuclein; D020559:Monomeric GTP-Binding Proteins; C499307:YPT6 protein, S cerevisiae; D020691:rab GTP-Binding Proteins