Figure 4.

SDS-insoluble aggregation is slowed by a stabilized Josephin domain. Formation of SDS-insoluble aggregates was analyzed over time, taking aliquots from an aggregation assay at 30 μM and pH 7.4. (A) A representative filter trap membrane shows the formation of SDS-insoluble aggregates formed from ataxin-3(Q64) and the stabilizing ataxin-3(Q64) mutants. (B) Densitometry is shown for ataxin-3(Q64) (black), ataxin-3(Q64) R103G (blue), ataxin-3(Q64) S81A (green), and ataxin-3(Q64) R103G S81A (purple). Analysis of the membrane by densitometry was completed on three independent experiments and fit to a sigmoidal curve.