Open AccessNanomolar oligomerization and selective co-aggregation of α-synuclein pathogenic mutants revealed by single-molecule fluorescence
Author(s) -
Emma Sierecki,
Nichole Giles,
Quill Bowden,
Mark Polinkovsky,
Janina Steinbeck,
Nicholas Arrioti,
Diya Rahman,
Akshay Bhumkar,
Philip R. Nicovich,
Ian L. Ross,
Robert G. Parton,
Till Böcking,
Yann Gambin
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep37630
Subject(s) - fibril , mutant , chemistry , protein aggregation , denaturation (fissile materials) , fluorescence , biophysics , mutation , monomer , alpha synuclein , amyloid (mycology) , synuclein , protein folding , biochemistry , microbiology and biotechnology , parkinson's disease , biology , gene , disease , medicine , pathology , inorganic chemistry , physics , organic chemistry , quantum mechanics , nuclear chemistry , polymer
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.