T123A mutation in ∆Np63α abrogates the inhibitory effect of CDK1 on ∆Np63α–mediated transcriptional regulation. (A–D), HEK293T cells were transfected with a mixture of K14-Luc or BPAG1-Luc and TK-Renilla, plus Flag-∆Np63α or its T123A mutant and My-CDK1 or shCDK1#1 plasmids, as indicated. IB analyses were performed to detect expression of indicated proteins in parallel. The K14-Luc or BPAG1-Luc expression levels were normalized to Renilla activity and presented as means ± SD (n = 3). Two-tailed t-test was used for comparison between two groups; ***, p < 0.001; **, p < 0.01; *, p < 0.05; ns, nonsignificant.