FIGURE 6.

Cdc42 Knockdown Activates the MAPK Pathway. A, control, Cdc42 knockdown, and Tuba knockdown MDCK cells were grown until confluence, and Western blotting was performed on cell lysate using antibodies against active (phosphorylated) ERK (pERK) and total ERK. Each sample was grown and analyzed in triplicate. All lanes shown were from the same blot with the same exposure. However, the Tuba lanes were separated from the other lanes, which is denoted by the space. B, measurement of the intensity of the bands showed that Cdc42 knockdown led to a significant increase in MAPK activation (p < 0.0004). MAPK activation in Tuba knockdown cells, although increased, did not reach statistical significance (p = 0.12).