title: Analysis of alpha-synuclein-associated proteins by quantitative proteomics.
abstract: To identify the proteins associated with soluble alpha-synuclein (AS) that might promote AS aggregation, a key event leading to neurodegeneration, we quantitatively compared protein profiles of AS-associated protein complexes in MES cells exposed to rotenone, a pesticide that produces parkinsonism in animals and induces Lewy body (LB)-like inclusions in the remaining dopaminergic neurons, and to vehicle. We identified more than 250 proteins associated with Nonidet P-40 soluble AS, and demonstrated that at least 51 of these proteins displayed significant differences in their relative abundance in AS complexes under conditions where rotenone was cytotoxic and induced formation of cytoplasmic inclusions immunoreactive to anti-AS. Overexpressing one of these proteins, heat shock protein (hsp) 70, not only protected cells from rotenone-mediated cytotoxicity but also decreased soluble AS aggregation. Furthermore, the protection afforded by hsp70 transfection appeared to be related to suppression of rotenone-induced oxidative stress as well as mitochondrial and proteasomal dysfunction.
authors.affiliation: Department of Pathology and Medicinal Chemistry, University of Washington School of Medicine, Seattle, Washington 98104, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Guangyu
authors.initials: G
authors.lastname: Gu
authors.forename: David R
authors.initials: DR
authors.lastname: Goodlett
authors.forename: Terry
authors.initials: T
authors.lastname: Zhang
authors.forename: Catherine
authors.initials: C
authors.lastname: Pan
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Montine
authors.forename: Kathleen S
authors.initials: KS
authors.lastname: Montine
authors.forename: Ruedi H
authors.initials: RH
authors.lastname: Aebersold
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002470:Cell Survival; D002853:Chromatography, Liquid; D003546:Cysteine Endopeptidases / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005434:Flow Cytometry; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D013058:Mass Spectrometry; D051379:Mice; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D009474:Neurons / Q000378:metabolism; D009502:Neutrons; D018384:Oxidative Stress; D011233:Precipitin Tests; D046988:Proteasome Endopeptidase Complex; D020543:Proteome; D040901:Proteomics / Q000379:methods*; D051381:Rats; D012402:Rotenone / Q000494:pharmacology; D015398:Signal Transduction; D051843:Synucleins; D013997:Time Factors; D014162:Transfection; D051844:alpha-Synuclein
chemical_list: D018840:HSP70 Heat-Shock Proteins; D009097:Multienzyme Complexes; D009419:Nerve Tissue Proteins; D020543:Proteome; C497605:Snca protein, mouse; C497606:Snca protein, rat; D051843:Synucleins; D051844:alpha-Synuclein; D012402:Rotenone; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex