Eps15 and Epsin1 Are Crucial for Enteropathogenic Escherichia coli Pedestal Formation Despite the Absence of Adaptor Protein 2

Enteropathogenic Escherichia coli (EPEC) are primarily extracellular pathogens that generate actin-rich structures known as pedestals during their pathogenesis. Surprising evidence has demonstrated that despite maintaining an extracellular location, EPEC require the endocytic protein, clathrin, for pedestal formation. To evaluate the strategies EPEC use to usurp endocytic machinery, we investigated the roles of a number of clathrin-coated pits components, adaptor protein 2 (AP-2), Eps15 and epsin1, during EPEC infections. We demonstrated that in conjunction with clathrin, pedestal formation also required the recruitment of Eps15 and epsin1 but not AP-2. Because AP-2 orchestrates the recruitment of clathrin, Eps15, and epsin1, as well as other adaptors, during assembly of clathrin-coated pits at the plasma membrane, our findings reveal a novel internalization subversion strategy employed by EPEC. These results further emphasize the recent paradigm that endocytic proteins are important for EPEC-mediated disease.