Figure 9. Antagonist effect of Pc peptide on CK2-mediated phosphorylation of a CK2β-dependent substrate.

Pre-formed CK2 complexes were incubated for 15 min at 4 °C with increasing concentrations of Pc peptide, followed by the addition of GST–Olig2 (5 μg) and 25 μM [γ-³²P]ATP/MgCl₂ for 5 min at room temperature. Phosphorylated proteins were separated by SDS/PAGE and analysed by autoradiography (upper panel) or Coomassie Blue staining (lower panel). The results are representative of two independent experiments. C, control without CK2. The molecular mass of the 45 kDa protein is indicated.