Marina de Bernard1, Beatrice Aricò, Emanuele Papini, Rosario Rizzuto, Guido Grandi, R Rappuoli, Carlomaurizio Montecucco
1Centro CNR Biomembrane and Dipartimento di Scienze Biomediche Sperimentali dell'Università di Padova, Italy.
Tóm tắt
Cells exposed to Helicobacter pylori toxin VacA develop large vacuoles that originate from massive swelling of membranous compartments of late stages of the endocytic pathway. To determine if the toxin is active from the cell cytosol, cells were either microinjected with toxin or transfected with plasmids encoding VacA. Both procedures cause formation of intracellular vacuoles. Cytosolic localization of the toxin was assessed by indirect immunofluorescence with specific antibodies and by expression of an active green fluorescence protein (GFP)–VacA chimera. Vacuoles induced by internally produced VacA are morphologically and functionally identical to those induced by externally added toxin. It is concluded that VacA is a toxin acting intracellularly by altering a cytosol‐exposed target, possibly involved in the control of membrane trafficking.
