Fig. 4.

Parkin-mediated regulation of DJ-1 is fully p53-dependent. (A) TSM1 neurons stably transfected with an empty vector (mock) or with wild-type parkin (PK) cDNA were examined for their p53- and actin-like immunoreactivities. Bars represent the densitometric analysis expressed as a percentage of control mock-transfected cells and are the means ± s.e.m. of 4 independent experiments. (B–E) p19^Arf−/− (white bars) and p19^Arf−/−p53^−/− (black bars) fibroblasts were transiently transfected with an empty vector (EV) or with wild-type parkin (PK) cDNAs. Twenty-four hours after transfection, cells were examined for DJ-1-, parkin- and actin-like immunoreactivities (B,C), human DJ-1 promoter transactivation (D) and mRNA levels (E). Bars indicate results as a percentage of control EV-transfected p19^Arf−/− cells and are the means ± s.e.m. of 4–11 independent experiments (6 replicates each). *P<0.05, **P<0.01; ns, not statistically significant.