The E. coli type III secreted effectors NleB and EspL interact with the microtubule associated protein ensconsin to disrupt vesicle trafficking, part 1

Enteropathogenic and enterohaemorrhagic E. coli (EPEC and EHEC) translocate a set of type III effector proteins into host cells that are critical for bacterial virulence. These effectors subvert normal host pathways by interacting with a variety of targets within the cell, but the binding partners and mechanism of action of the majority of effectors are not understood. We identified the microtubule associated protein, ensconsin, as a novel target for two EPEC/EHEC effectors. We found that the secreted effectors NleB and EspL bind host ensconsin and work synergistically to paralyze kinesin-based intracellular vesicular transport. Our findings demonstrate that EPEC/EHEC encode multiple effectors that control intracellular vesicle movement and suggest a simple strategy for broad-based immobilization of host cells by pathogens.