+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: not found

      Formation of Toxic Oligomeric α-Synuclein Species in Living Cells


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          Misfolding, oligomerization, and fibrillization of α-synuclein are thought to be central events in the onset and progression of Parkinson's disease (PD) and related disorders. Although fibrillar α-synuclein is a major component of Lewy bodies (LBs), recent data implicate prefibrillar, oligomeric intermediates as the toxic species. However, to date, oligomeric species have not been identified in living cells.

          Methodology/Principal Findings

          Here we used bimolecular fluorescence complementation (BiFC) to directly visualize α-synuclein oligomerization in living cells, allowing us to study the initial events leading to α-synuclein oligomerization, the precursor to aggregate formation. This novel assay provides us with a tool with which to investigate how manipulations affecting α-synuclein aggregation affect the process over time. Stabilization of α-synuclein oligomers via BiFC results in increased cytotoxicity, which can be rescued by Hsp70 in a process that reduces the formation of α-synuclein oligomers. Introduction of PD-associated mutations in α-synuclein did not affect oligomer formation but the biochemical properties of the mutant α-synuclein oligomers differ from those of wild type α-synuclein.


          This novel application of the BiFC assay to the study of the molecular basis of neurodegenerative disorders enabled the direct visualization of α-synuclein oligomeric species in living cells and its modulation by Hsp70, constituting a novel important tool in the search for therapeutics for synucleinopathies.

          Related collections

          Most cited references18

          • Record: found
          • Abstract: found
          • Article: not found

          Common structure of soluble amyloid oligomers implies common mechanism of pathogenesis.

          Soluble oligomers are common to most amyloids and may represent the primary toxic species of amyloids, like the Abeta peptide in Alzheimer's disease (AD). Here we show that all of the soluble oligomers tested display a common conformation-dependent structure that is unique to soluble oligomers regardless of sequence. The in vitro toxicity of soluble oligomers is inhibited by oligomer-specific antibody. Soluble oligomers have a unique distribution in human AD brain that is distinct from fibrillar amyloid. These results indicate that different types of soluble amyloid oligomers have a common structure and suggest they share a common mechanism of toxicity.
            • Record: found
            • Abstract: found
            • Article: not found

            alpha-Synuclein in filamentous inclusions of Lewy bodies from Parkinson's disease and dementia with lewy bodies.

            Lewy bodies and Lewy neurites are the defining neuropathological characteristics of Parkinson's disease and dementia with Lewy bodies. They are made of abnormal filamentous assemblies of unknown composition. We show here that Lewy bodies and Lewy neurites from Parkinson's disease and dementia with Lewy bodies are stained strongly by antibodies directed against amino-terminal and carboxyl-terminal sequences of alpha-synuclein, showing the presence of full-length or close to full-length alpha-synuclein. The number of alpha-synuclein-stained structures exceeded that immunoreactive for ubiquitin, which is currently the most sensitive marker of Lewy bodies and Lewy neurites. Staining for alpha-synuclein thus will replace staining for ubiquitin as the preferred method for detecting Lewy bodies and Lewy neurites. We have isolated Lewy body filaments by a method used for the extraction of paired helical filaments from Alzheimer's disease brain. By immunoelectron microscopy, extracted filaments were labeled strongly by anti-alpha-synuclein antibodies. The morphologies of the 5- to 10-nm filaments and their staining characteristics suggest that extended alpha-synuclein molecules run parallel to the filament axis and that the filaments are polar structures. These findings indicate that alpha-synuclein forms the major filamentous component of Lewy bodies and Lewy neurites.
              • Record: found
              • Abstract: found
              • Article: not found

              Visualization of interactions among bZIP and Rel family proteins in living cells using bimolecular fluorescence complementation.

              Networks of protein interactions coordinate cellular functions. We describe a bimolecular fluorescence complementation (BiFC) assay for determination of the locations of protein interactions in living cells. This approach is based on complementation between two nonfluorescent fragments of the yellow fluorescent protein (YFP) when they are brought together by interactions between proteins fused to each fragment. BiFC analysis was used to investigate interactions among bZIP and Rel family transcription factors. Regions outside the bZIP domains determined the locations of bZIP protein interactions. The subcellular sites of protein interactions were regulated by signaling. Cross-family interactions between bZIP and Rel proteins affected their subcellular localization and modulated transcription activation. These results attest to the general applicability of the BiFC assay for studies of protein interactions.

                Author and article information

                Role: Editor
                PLoS ONE
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                2 April 2008
                : 3
                : 4
                : e1867
                [1 ]Alzheimer's Research Unit, MassGeneral Institute for Neurodegenerative Disease, MGH Harvard Medical School, Charlestown, Massachusetts, United States of America
                [2 ]Instituto de Medicina Molecular, Cell and Molecular Neuroscience Unit, Instituto de Fisiologia, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
                Massachusetts Institute of Technology, United States of America
                Author notes

                Conceived and designed the experiments: BH TO RS PM. Performed the experiments: TO PP JT RS MK FC. Analyzed the data: TO PP. Contributed reagents/materials/analysis tools: TO PP PM. Wrote the paper: BH TO PM.

                Outeiro et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
                : 12 September 2007
                : 20 February 2008
                Page count
                Pages: 9
                Research Article
                Biochemistry/Protein Folding
                Cell Biology/Neuronal and Glial Cell Biology
                Neurological Disorders/Cognitive Neurology and Dementia
                Neurological Disorders/Movement Disorders



                Comment on this article