Dopamine-induced conformational changes in alpha-synuclein.

• Main Authors: Tiago F Outeiro, Jochen Klucken, Kathryn Bercury, Julie Tetzlaff, Preeti Putcha, Luis M A Oliveira, Alexandre Quintas, Pamela J McLean, Bradley T Hyman
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2009-09-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC2731858?pdf=render

Oligomerization and aggregation of alpha-synuclein molecules play a major role in neuronal dysfunction and loss in Parkinson's disease [1]. However, alpha-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 alpha-synuclein by inhibiting the formation of or by disaggregating amyloid fibrils [5], [6], [7].Here, we show that alpha-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 alpha-synuclein which could be prevented by blocking dopamine transport into the cell. Dopamine also induced conformational changes in alpha-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 alpha-synuclein in neurons, which may help explain the increased vulnerability of dopaminergic neurons in Parkinson's disease.