Fig. S5.

The translation repressor 4E-BP1 is crucial for mediating FGF response in chondrocytes. RCS cells were infected with either 4E-BP1 or nonsilencing (ns) shRNAs. (A) S-phase levels in the indicated cell lines treated with FGF1 were assayed by BrdU incorporation. (B) RCS cells overexpressing either ns or 4E-BP1 shRNAs were treated with FGF1, and equal amounts of protein extracts were incubated with agarose-conjugated eIF4E antibody. Two separate samples were used for the cells overexpressing 4E-BP1 shRNA (lanes 2a and 2b and lanes 4a and 4b). Two exposures are shown for 4E-BP1 WB to demonstrate that 4E-BP1 is dephosphorylated similarly in both cell lines.