FIG. 3.

Activation of RhoA GTPase by O. tsutsugamushi infection. (A) Activation of small GTPases was examined by performing GST pull-down assays using rhotekin (for RhoA) or PAK1-PBD (for Cdc42 and Rac1) fusion proteins as described in Materials and Methods. RhoA was activated upon bacterial infection, but Cdc42/Rac1 was not activated. The GTPase active forms bound to GTPγ-S were used as positive controls. CNT, control. (B) Inhibition of intracellular invasion of O. tsutsugamushi by C. botulinum C3 exoenzyme, an inhibitor of RhoA family GTPases. HeLa cells were treated with the exoenzyme in the presence of Lipofectamine (C3/Lipo) or in the presence of only Lipofectamine (Lipo). P values were determined using a two-tailed Student t test (*, P < 0.01).