A Cytotoxic Type III Secretion Effector of Vibrio parahaemolyticus Targets Vacuolar H+-ATPase Subunit c and Ruptures Host Cell Lysosomes
Figure 1
VepA is cytotoxic only inside cells.
(A) Representative images of 293T cells transfected with GFP-fused VepA or VepAΔC. Actin was stained with rhodamine-phalloidin to visualize the cells. Scale bar, 200 µm. (B) The indicated proteins were delivered into HeLa cells using the HVJ envelope, or HeLa cells were treated with 100 µg ml−1 VepA without HVJ; cytotoxicity was determined after 4 h. The values represent the mean ± SD for a minimum of three independent experiments. (C) HeLa cells were infected with the indicated strains for 4 h and analyzed for lactate dehydrogenase (LDH) release as a measure of cytotoxicity. *P<0.01. (D) Secretion of VepA or VepAΔC. The indicated strains were grown in LB broth for 6 h, and the secreted proteins were subjected to immunoblot analysis using an anti-VepA antibody. The migration positions of the molecular weight markers are indicated on the left side of the panel.