FIG. 3.

The binding of FGF-2 to its receptors is augmented in glypican-1-deficient myoblasts. (A) FGF-2 cell surface receptors of WT myoblasts transiently transfected with or without shCtrl and shGly, and of C6 myoblasts transiently transfected with or without rat glypican-1 (C6-Gly), were affinity cross-linked to ¹²⁵I-FGF-2 at 4°C. Cell extracts were separated on SDS-PAGE and then exposed to a phosphorimager (left). As shown on the right, the gel was stained with Coomassie blue as a loading control. (B) The same extracts described for panel A (left) were analyzed by Western blotting to determine the total protein levels of FGFR-I and FGFR-IV. GAPDH levels were used as a loading control. (C) Myoblasts were treated with or without Hase, and then FGFRs were affinity cross-linked to ¹²⁵I-FGF-2 at 4°C in the presence or absence of an excess of cold FGF-2. As shown on the right, the gel was stained with Coomassie blue as a loading control.