Fig 14.

DJ-1 inhibits transcriptional activity of p53 to the p21 promoter under conditions of oxidative stress in a manner dependent on DNA affinity. (A) H1299 cells were cotransfected with pGL4.12-p21-luciferase and expression vectors for FLAG-p53 mutants and for wild-type or C106S DJ-1–HA. Twenty-four hours after transfection, their luciferase activities were examined. Values are means ± SE (n = 3 experiments). *, P < 0.05; **, P < 0.01. H1299 cells were cotransfected with pGL4.12-p21-luciferase and an expression vector for wild-type or C106S DJ-1–HA together with a vector for FLAG-p53 R181L (B) or FLAG-p53 R181C (C). Twenty-four hours after transfection, the cells were treated with H₂O₂ and cycloheximide (CHX) as described for Fig. 6, and their luciferase activities were examined. (D and E) Proteins were prepared from H1299 cells transfected with FLAG-p53 mutants and wild-type or C106S DJ-1–HA and analyzed by Western blotting.