Figure 4.

MSG1 enhances transcription mediated by full-length Smad4 in mammalian cells. (A) MDA-MB-468 cells (Smad4-deficient) were cotransfected with a GAL4DB fusion of full-length Smad2, full-length Smad4 (without fusion), TβRI(T204D), HA-MSG1, together with pG5CAT reporter followed by incubation in the presence of 10% fetal calf serum for 16 h and CAT assay. Results are mean ± SEM of three independent experiments. (B) HepG2 cells were cotransfected with FAST-1, HA-MSG1 [wild type (wt) or a deletion mutant lacking the CR2 transactivating domain (ΔCR2)] together with an ARE-dependent luciferase reporter plasmid. Transfected cells were treated with TGFβ₁ (5 ng/ml) for 16 h in the presence of 0.2% fetal calf serum, and the luciferase activity was determined. Results are mean ± SEM of duplicate measurements of triplicate wells from a representative experiment.