Fig. 5. Radicicol does not inhibit Elk phosphorylation. Cells were transiently transfected with Elk and subsequently treated for 36–40 h with radicicol or MEK inhibitors. Cell extracts were analyzed by Western blotting for phosphorylation status of Elk. Blots were first probed with anti-phospho-Elk (top panels) and subsequently stripped and reprobed with anti-Elk (bottom panels). A, ras-transformed NIH3T3 cells. B, MEK-1-S218D,S222D-infected NIH3T3 cells.