Author response image 1. 24 hr and 48 hr of Activin treatment partially recapitulate the untreated condition for pathway activation and induction of target genes.
(A) Western blot for pSMAD2, SMAD2/3 and TUBULIN (loading control) on lysates collected from cells treated overnight with SB-431542, followed by washout and stimulation for the indicated times with the concentrations of Activin shown, or left untreated from plating to harvest (48 hr). (B) qPCR on samples treated as in (A) for representative target genes. Plotted are the means and SEM of three independent experiments performed in duplicate. *** corresponds to a p-value of < 0.001; ** corresponds to a p-value of < 0.01; n.s., non-significant.