Figure 7.

Exposure of HeLa cells to IMV leads to rac1 activation. (A) shows a representative Western blot of rac1-GTP levels in cell lysates that were either incubated for 60 min in serum-free DMEM (control) or for the indicated times in serum-free DMEM containing purified IMV at an MOI of 40 (IMV). Rac1-GTP was affinity isolated from cell lysates and was detected by ECL. (B) shows the quantitation of four independent experiments. Western blots were probed with antirac1 and antimouse ³⁵SLR, and the blots were quantified by phosphoimager. The average counts of uninfected cells incubated for 60 min in serum-free DMEM (black bar, 60 min) from four experiments was taken as 100%. The gray bars are from HeLa cells exposed to IMV for different periods of time.