Accordingly, we monitored the dependence of Smad-responsive genes on the presence of Bptf in ES cells. ES cells readily responded to activin-A as monitored by the phosphorylation of Smad2 (Figure S22A, Figure S22B). From these experiments we identified a number of Smad-dependent genes which completely or partially require Bptf for full activation. Genes requiring Bptf for full activation include Cer1, Gsc and T (Figure 5A). Genes which partially require Bptf include FGF8, Lefty1 and p21 (Figure 5A) (Figure S23).
