Type 3 secretion effectors

Enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and Shigella use a type 3 secretion system (T3SS) to inject dozens of effector proteins into the host cell. The effectors manipulate host cell processes including the host cytoskeleton, immune response, cell survival, and gut integrity. EPEC and EHEC share a large number of common effectors and some homologous effectors can be found in Shigella, however there is also considerable variability within and between pathotypes. For many effectors detailed molecular mechanisms of action have been described by identifying host interacting partners, homologous proteins, or enzymatic activities. However, understanding effector biology within the context of infection with multiple effectors, various cell populations, and host genetic differences remains a challenge.