Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional housekeeping protein reported to be a target of several covalent modifications in many organisms. In a previous study, enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli strains were shown to secrete GAPDH and the protein to bind human plasminogen and fibrinogen. Here we report that GAPDH of these pathogens is ADP-ribosylated either in the cytoplasm or in the extracellular medium. GAPDH catalyzes its own modification, which involves Cys-149 at the active site. ADP-ribosylation of extracellular GAPDH may play an important role in the host-pathogen interaction, as also proposed in other pathogens. [Int Microbiol 2009; 12(3):187-192
