FIG. 3.

Expression of wild-type p53 in the absence of cellular damage decreases 53BP2 levels. (A) Western blot of lysates (30 μg of total protein per lane) prepared from 041TR cells at the indicated times after tetracycline withdrawal. The decreases in 53BP2 protein, as a fraction of baseline levels determined at time zero, are indicated below, normalized for tubulin. 53BP2 was detected with monoclonal antibody DX547; p53 was detected with monoclonal antibody 1801. (B) Northern blot of total RNA (15 μg/lane) prepared from the 041TR cells above at the indicated time points, probed for 53BP2, stripped, and reprobed for GAPDH. The decreases in 53BP2 mRNA, as a fraction of baseline levels determined at time zero, are indicated below, normalized for GAPDH.