Enteroaggregative Escherichia coli plasmid-encoded toxin.

Plasmid-encoded toxin (Pet) is secreted by enteroaggregative Escherichia coli (EAEC), a pathotype of diarrhogenic E. coli. EAEC infection is an important cause of diarrhea in outbreak and nonoutbreak settings in developing and developed countries. EAEC secretes Pet by using the type V secretion system. Mature secreted Pet is a serine protease and its eukaryotic target is the actin-binding protein alpha-fodrin. When Pet cleaves alpha-fodrin in the target cell cytosol, the organization of the actin cytoskeleton is disrupted. The loss of actin filament structure results in cell rounding and detachment from the substratum. This article summarizes the long trip of Pet during its biogenesis, its interaction with epithelial cells, intracellular trafficking and mechanism of action.