Fig. 7. Constitutively active forms of RhoA and Rac1 rescue pore-forming activity in the presence of YopE or YopT. HeLa cells were not transfected (non transf.) or were transfected with an empty vector (pCGT), pCGTRhoA-V14 (pRhoA-V14) or pCGTRac1-V12 (pRac1-V12). (A) LDH released from HeLa cells infected with YP6/vector, YP6/pYopE or YP6/pYopT for 3 h was determined as described in the legend to Figure 2. (B) Expression of RhoA-V14 and Rac1-V12 in HeLa cells was evaluated 24 h post transfection by immunoblotting. Transfected cells were lysed in detergent and samples of soluble protein equivalent to 1 × 10⁴ HeLa cells were analyzed by immunoblotting with a monoclonal antibody that recognizes the T7 epitope tag appended to RhoA-V14 and Rac1-V12. Duplicate samples of protein were analyzed by immunoblotting with a monoclonal antibody specific for the Raf kinase, to control for loading.