Figure 4.

Deletion of the middle region does not affect Smad3 nuclear accumulation: COS-7 cells were transfected with expression vectors for the wild-type 6myc-Smad3 protein or the Smad3 Δ200–230 mutant in the absence or in the presence of the constitutively active ALK5 receptor as indicated on the right. Immunofluorescence was performed using the anti-myc (9E10) monoclonal antibody followed by a secondary, FITC-conjugated, antibody. Smad proteins were visualized by fluorescence microscopy. Representative DAPI staining of the transfected cells is also shown.