Fig. 2.

Δ133p53 suppresses p53 and p73 transcriptional activities. (A) Transcriptional activities of p53 (Left) and p73 (Right) were determined using PG13-Luc reporter in SNU-1 cells following cotransfection with Δ133p53 at the indicated molar ratios. Luciferase activity in cells transfected with an empty vector (Vect) is arbitrarily set at 1. (B) Same as in A, but p21-pWWP-Luc reporter was used. (C) p53-null cells, Kato III, were cotransfected with Δ133p53 and p53 (Left) or p73 (Right) at the indicated ratios and analyzed for expression of p21 and NOXA proteins by Western blotting. (D) Expression of p21 and NOXA proteins was analyzed in SNU-1 cells, in which levels of endogenous Δ133p53 isoform were suppressed with shRNA. (Right) shRNA plasmid selectively targets the ∆133p53 isoform but not p53.