Fig. 7. PKC phosphorylates N-terminal Ser residues of ß-catenin in vivo. (A) HEK293 reporter cells were incubated with A23187 (2.5 µM) and BIM (5 µM) for 15 h in the absence or presence of Wnt3a-CM. Cytosolic fractions were prepared and subjected to western blot analysis with anti-phospho-p45-ß-catenin, anti-phospho-p33/37-ß-catenin or anti-ß-catenin antibody. The same amount of ß-catenin was loaded in each lane. (B) HEK293 cells were transfected with negative control (NC) siRNA (40 µmol) and PKC siRNA (20 and 40 µmol) for 48 hours and then cell lysates were subjected to western blot analysis with anti-PKC, anti-ß-catenin, anti-p45-ß-catenin, anti-p33/37-ß-catenin and anti-actin antibodies. (C) HEK293 reporter cells were transfected with negative control siRNA (40 µmol) and PKC siRNA (40 µmol) for 48 hours and then luciferase activity was measured. The results are the average of three experiments, and the bars indicated standard deviation.