Fig. 3.

GSH has no effect on TGF-β-induced Smad phosphorylation and/or nuclear translocation. A: effect of GSH on TGF-β-induced phosphorylation of Smad2/3. B: effect of GSH on TGF-β-induced nuclear translocation of pSmad2/3 and Smad4. NIH/3T3 cells were treated with TGF-β (1 ng/ml) in the presence or absence of GSH (5 mM). The cells were collected at different time points as indicated. Cell lysates and nuclear extracts were prepared, and equal amounts of cell lysates or nuclear extract (50 µg/lane) were subjected to SDS-PAGE. Western blotting was performed using specific antibodies as described in materials and methods. TATA binding protein (TBP) was used as a loading control for nuclear proteins.