(C) FBW7α immunoblot eluted from the agarose bead-bound peptide, which had been incubated with the recombinant SCF-FBW7α for 1 hour at 37◦C. The agarose bead-bound peptide contains either the non-phosphorylated SOX9 amino acid sequence spanning from residue number 231 to 245 (SOX9 peptide), or those with the threonine corresponding to residue number 236 and 240 being phosphorylated (pSOX9 peptide). The input (10%) showed the level of the supplemented recombinant SCF-FBW7α in the in vitro binding reaction. Shown blot is representative from 2 independent experiments. 