FIGURE 4.

TEAD-dependent suppression of ΔNp63 by TAZ. A, TEAD knockdown diminishes TAZ-induced repression of ΔNp63 protein. Transient siRNA knockdown of TEAD1/3/4 (siTEAD) was performed in MCF10A cells with inducible expression of TAZ-S89A. An siRNA targeting a nonspecific sequence was used as a negative control (siCtrl). Twenty-four hours post-transfection, cells were induced (+) or not (−) with Dox. Protein was extracted 48 h postinduction, and ΔNp63 expression was assessed in cells with and without TAZ-S89A expression. β-Actin was used as an internal loading control. B, knockdown of TEAD abolishes TAZ-induced suppression of ΔNp63 mRNA. qRT-PCR analysis of ΔNp63 mRNA was performed. Cell lines and treatment conditions were as described in A. C, knockdown of TEAD by siRNA partially blocks TAZ-induced suppression of ΔNp63 promoter activity. D, expression of TEAD in MCF10A-WPI, MCF10A-TAZ, SK-Luci6, and SK-BR3 cells. E, TAZ fails to inhibit TAZ promoter in TEAD-negative SK-Luci6 cells. Luciferase analysis was performed as described in Fig. 2E. The experiment was performed in triplicate, and error bars represent S.D. from each set of triplicates. *, statistically significant difference (p < 0.05).