title: Nanomolar oligomerization and selective co-aggregation of α-synuclein pathogenic mutants revealed by single-molecule fluorescence.
abstract: Protein aggregation is a hallmark of many neurodegenerative diseases, notably Alzheimer's and Parkinson's disease. Parkinson's disease is characterized by the presence of Lewy bodies, abnormal aggregates mainly composed of α-synuclein. Moreover, cases of familial Parkinson's disease have been linked to mutations in α-synuclein. In this study, we compared the behavior of wild-type (WT) α-synuclein and five of its pathological mutants (A30P, E46K, H50Q, G51D and A53T). To this end, single-molecule fluorescence detection was coupled to cell-free protein expression to measure precisely the oligomerization of proteins without purification, denaturation or labelling steps. In these conditions, we could detect the formation of oligomeric and pre-fibrillar species at very short time scale and low micromolar concentrations. The pathogenic mutants surprisingly segregated into two classes: one group forming large aggregates and fibrils while the other tending to form mostly oligomers. Strikingly, co-expression experiments reveal that members from the different groups do not generally interact with each other, both at the fibril and monomer levels. Together, this data paints a completely different picture of α-synuclein aggregation, with two possible pathways leading to the development of fibrils.
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Emma
authors.initials: E
authors.lastname: Sierecki
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Nichole
authors.initials: N
authors.lastname: Giles
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Quill
authors.initials: Q
authors.lastname: Bowden
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Polinkovsky
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia QLD 4072, Australia.
authors.forename: Janina
authors.initials: J
authors.lastname: Steinbeck
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia QLD 4072, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Arrioti
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia QLD 4072, Australia.
authors.forename: Diya
authors.initials: D
authors.lastname: Rahman
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Akshay
authors.initials: A
authors.lastname: Bhumkar
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Philip R
authors.initials: PR
authors.lastname: Nicovich
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia QLD 4072, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Ross
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, St Lucia QLD 4072, Australia.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Parton
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Till
authors.initials: T
authors.lastname: Böcking
authors.affiliation: EMBL Australia Node in Single Molecule Science, The University of New South Wales, Sydney NSW 2032 Australia.
authors.forename: Yann
authors.initials: Y
authors.lastname: Gambin
mesh_terms: D005453:Fluorescence; D008954:Models, Biological; D008970:Molecular Weight; D050505:Mutant Proteins / Q000737:chemistry* / Q000648:ultrastructure; D053758:Nanoparticles; D066329:Protein Aggregates; D066263:Protein Aggregation, Pathological; D014176:Protein Biosynthesis; D055503:Protein Multimerization; D000072760:Single Molecule Imaging / Q000379:methods*; D013696:Temperature; D014461:Ultracentrifugation; D051844:alpha-Synuclein / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D050505:Mutant Proteins; D066329:Protein Aggregates; D051844:alpha-Synuclein