Fig. 5

A53T α-synuclein over-expression is associated with inhibition of 26S proteasome catalytic activity. Adult wild-type rats received stereotaxic injection of AAV-Empty or AAV-TdTomato (TdT) into the left SNpc and AAV-A53T into the right SNpc. Animals were culled at 1 wpi before isolation of left and right midbrain tissue. a-b Native PAGE assay of 26S proteasome activity and subsequent immunoblotting of β5 proteasome subunit levels were compared between left (AAV-Empty (a) or AAV-TdTomato (b)) and right (AAV-A53T) midbrain samples. Quantification by densitometry and normalisation to proteasome subunit levels revealed that A53T α-synuclein over-expression was associated with significant inhibition of 26S catalytic activity. Data are individual percentage values expressed relative to mean of control group (*p < 0.05, **p < 0.01; paired t-test; n = 6 per group). c Representative immunoblot comparing Rpt6 and β5 proteasome subunit levels in midbrain samples expressing AAV-Empty, AAV-TdTomato or AAV-A53T. Quantification by densitometry and normalisation to tubulin loading control revealed no significant change in expression level of either subunit. Data are percentage mean expressed relative to mean of AAV-empty control group +/− SEM (β5 subunit - p = 0.8034, Rpt6 subunit- p = 0.4902; one-way ANOVA; n = 4–6 per group)