Figure 2.

Bacterial effectors regulating T3-pore formation. Upon cell contact and T3SS activation, the Yersinia YopB/D translocon components activate Rho GTPases leading to the polymerization of actin and T3-pore formation. The injected T3 effectors, such as YopK, YopE, and YopT, downregulate T3-pore formation and effector translocation. YopK directly acts on the T3 translocon. YopE and YopT inhibit RhoGTPases. EspZ shares an activity related to that of YopK by binding to the EPEC T3 translocon, inhibiting T3-pore formation and effector injection. EspC downregulates T3 pore by degrading the translocator components EspA/D, an activity shared by the EHEC EspP. EspP also downregulate the Hly PFT inserted in plasma membranes.