Figure 5. DUSP4 regulated Smad4 expression through ubiquitination. (A) Western blot analysis of DUSP4 and Smad4 expression in DUSP4 overexpression-treated HCT116 cells with CQ and MG132 treatment at different time points. (B) CO-IP analysis of DUSP4 and Smad in SW480 cells. (C) Forward and reverse CO-IP analysis of DUSP4 and Smad in SW480 cells and HCT116 cells. (D) Immunocolocalization analysis of DUSP4 and Smad in SW480 cells and HCT116 cells. (E) Ubiquitination test of DUSP4 and Smad in HCT116 cells. (F) Ubiquitination test of DUSP4 and Smad in SW480 cells. Scale bar: 5 μm.