Structural Microengineers: Pathogenic Escherichia coli Redesigns the Actin Cytoskeleton in Host Cells

Several virulent bacteria have the ability to manipulate the host cell actin cytoskeleton as part of their pathogenic strategy. These pathogens subvert the host cell actin polymerization machinery for various purposes including motility within host cells, cell-to-cell spread, and to prevent phagocytic engulfment by professional phagocytes. In contrast to intracellular pathogens, pathogenic Escherichia coli (including both enterohemorrhagic and enteropathogenic E. coli) subvert actin polymerization from an extracellular position to facilitate adherence. This review summarizes recent data on the mechanisms by which pathogenic E. coli hijack members of the Wiskott-Aldrich syndrome protein family to manipulate actin polymerization within host cells, including the novel, and surprisingly simple, mechanism recently revealed for the EspF_u effector.