Sporadic SNCA Mutations A18T and A29S Exhibit Variable Effects on Protein Aggregation, Cell Viability and Oxidative Stress

Background: α-synuclein aggregation is the hallmark feature of Parkinson's disease. Both familial and sporadic forms of the disease exhibit this feature. Several mutations have been identified in patients and are associated with the disease pathology.

Methods And Results: We have used site-directed mutagenesis to generate α-synuclein mutant variants tagged with GFP. Fluorescence microscopy, flow cytometry, western blotting, cell viability and oxidative stress analysis were performed to investigate the effect of two less studied α-synuclein variants. In this study we characterized two less studied α-synuclein mutations, A18T and A29S, in the well-established yeast model. Our data shows variable expression, distribution and toxicity of the protein in the mutant variants A18T, A29S, A53T and WT. The cells expressing the double mutant variant A18T/A53T showed the most increase in the aggregation phenotype and also depicted reduced viability suggesting a more substantial effect of this variant.

Conclusion: The outcome of our study highlights the variable localization, aggregation phenotype and toxicity of the studied α-synuclein variants. This underscores the importance of in-depth analysis of every disease-associated mutation which may result in variable cellular phenotype.