The Yeast Parkinson's Disease Model Exhibits An Increase in Peroxisome Number Independent of the Division Proteins Vps1 and Dnm1.

Aggregation of α-Synuclein is a hallmark characteristic of Parkinson's disease. Several mutant variants of α-Synuclein linked to the disease that exhibit distinct patterns of localization, aggregation dynamics, and cellular toxicity have been reported. This variability underscores the need for a detailed study of each mutant variant to understand the disease pathology better. While mitochondria have been extensively studied for their role in Parkinson's disease pathogenesis, much less is known about peroxisomes, organelles that share important functions with mitochondria. To address this, we investigated the effect of expression of WT- α-Synuclein and two disease variants A53T and A29S in yeast. Interestingly, the expression of the A53T α-Synuclein variant resulted in a significant increase in peroxisome number per cell. This increase was also observed in cells lacking peroxisome fission proteins Vps1 and Dnm1. Our data also suggests a link between the aggregation propensity of α-Synuclein and the observed effect on peroxisome number. Expression of the A29S variant of α-Synuclein and WT-α-Synuclein which exhibits a lower aggregation propensity than A53T, did not result in a similar increase in peroxisome number. In line with this, enhanced mitochondrial fragmentation was observed only upon expression of A53T α-Synuclein in WT yeast cells.