FIG. 4.

Myoblasts deficient in glypican-1 are more sensitive to FGF-2 but not to other heparin binding growth factors. (A) WT and C6 myoblasts were treated with the indicated concentrations of FGF-2 for 5 min. Cell extracts were analyzed for phospho-ERK1/2 by immunoblotting. The levels of total ERK1/2 were used as a loading control. On the right, a quantification of two independent experiments is shown. (B) C6 myoblasts were transiently transfected with or without rat glypican-1 (C6-Gly), and at 48 h after transfection, the cells were treated as described for panel A. A quantification of this experiment is shown on the right. (C) WT and C6 myoblasts were treated with the indicated concentrations of TGF-β-1 and PDGF for 15 min or HGF for 5 min. The levels of phospho-Smad 2 or phospho-ERK1/2 were determined by immunoblot analysis. GAPDH or total ERK1/2 levels were used as a loading control.