A native interactor scaffolds and stabilizes toxic Ataxin-1 oligomers in SCA1
- Baylor College of Medicine, United States
- University of Texas Medical Branch, United States
- Howard Hughes Medical Institute, Baylor College of Medicine, United States
- University of Minnesota, United States
Abstract
Recent studies indicate that soluble oligomers drive pathogenesis in several neurodegenerative proteinopathies, including Alzheimer and Parkinson disease. Curiously, the same conformational antibody recognizes different disease-related oligomers, despite the variations in clinical presentation and brain regions affected, suggesting that the oligomer structure might be responsible for toxicity. We investigated whether polyglutamine-expanded Ataxin1, the protein that underlies spinocerebellar ataxia type 1, forms toxic oligomers and, if so, what underlies their toxicity. We found that mutant ATXN1 does form oligomers and that oligomer levels correlate with disease progression in the Atxn1154Q/+ mice. Moreover, oligomeric toxicity, stabilization and seeding require interaction with Capicua, which is expressed at greater ratios with respect to ATXN1 in the cerebellum than in less vulnerable brain regions. Thus, specific interactors, not merely oligomeric structure, drive pathogenesis and contribute to regional vulnerability. Identifying interactors that stabilize toxic oligomeric complexes could answer longstanding questions about the pathogenesis of other proteinopathies.
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Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols (#AN-1013) of Baylor College of Medicine
Copyright
© 2015, Lasagna-Reeves et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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A native interactor scaffolds and stabilizes toxic Ataxin-1 oligomers in SCA1
eLife 4:e07558.
https://doi.org/10.7554/eLife.07558
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