Ataxin-3 Stage 1-aggregation kinetics are changed by the Josephin mutants. Stage 1 aggregation was monitored using thioT fluorescence at 30 μM and pH 7.4 with a fluorescence plate reader. Wild-type (black), R103G (blue), S81A (green), R103G S81A (purple), and L169H (red) are shown in (A) Ataxin-3(Q64), (B) ataxin-3(Q15), and (C) Josephin.