FIG 6.

CD99 peptide inversely regulates FAK phosphorylation at Y397 and S910 via a MAPK signaling cascade. (A) Cells were treated with CD99CRIII3 peptide in a dose-dependent manner. Levels of FAK phosphorylation at Y397 and S910 were assessed by Western blotting. (B) MCF-7 cells were transiently transfected with HRAS siRNA or dominant negative RAF1 and incubated with CD99CRIII3 for 1 h. Cell lysates were separated by SDS-PAGE and analyzed by Western blotting with the antibodies indicated. (C) Cells were dose-dependently treated with the MEK inhibitor PD98059 and incubated with CD99CRIII3 for 1 h. Western blotting was performed with the antibodies indicated. The graphs show the phosphorylated FAK intensities of bands normalized against the total FAK level. β-Actin was used as a loading control.