Title
Dopamine-Induced Conformational Changes in Alpha-Synuclein
Author
Tiago F. Outeiro, Jochen Klucken, Kathryn Bercury, Julie Tetzlaff, Preeti Putcha, Luis M. A. Oliveira, Alexandre Quintas, Pamela J. McLean, Bradley T. Hyman
Year
2009
Journal
PLoS ONE
Abstract
Oligomerization and aggregation of α-synuclein molecules play a major role in neuronal dysfunction and loss in Parkinson's disease [1]. However, α-synuclein oligomerization and aggregation have mostly been detected indirectly in cells using detergent extraction methods [2], [3], [4]. A number of in vitro studies showed that dopamine can modulate the aggregation of α-synuclein by inhibiting the formation of or by disaggregating amyloid fibrils [5], [6], [7]. Here, we show that α-synuclein adopts a variety of conformations in primary neuronal cultures using fluorescence lifetime imaging microscopy (FLIM). Importantly, we found that dopamine, but not dopamine agonists, induced conformational changes in α-synuclein which could be prevented by blocking dopamine transport into the cell. Dopamine also induced conformational changes in α-synuclein expressed in neuronal cell lines, and these changes were also associated with alterations in oligomeric/aggregated species. Our results show, for the first time, a direct effect of dopamine on the conformation of α-synuclein in neurons, which may help explain the increased vulnerability of dopaminergic neurons in Parkinson's disease.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Chemical stability, Aggregation, Biochemistry