Figure 2.
A COL7A1 SBS tandem repeat confers TGF-β responsiveness to a heterologous promoter. Confluent fibroblast cultures were transfected with several constructs derived from pBLCAT5 by the calcium phosphate/DNA coprecipitation procedure. These constructs contained one copy of the COL7A1 SBS (SBS-TK/CAT), two copies of the SBS [(SBS)2-TK/CAT], or two copies of a mutated SBS [(SBSmut)2-TK/CAT]. After glycerol shock, the cultures were incubated in fresh medium containing 1% fetal calf serum, without (−) or with (+) TGF-β (10 ng/ml) added to the medium 4 h later. After 40 h of incubation, cell extracts were assayed for CAT activity. Results are the mean ± SD of three independent experiments.