Fig. 4. Reduced Rab5 and enhanced Rab7 content of MBSA-MDP-treated cells is sufficient to drive lysosomal targeting. To determine the role of Rab5 and Rab7 content of MBSA-MDP-treated cells in lysosomal targeting of Salmonella, reconstitution of the phagosome-lysosomes transport assay was carried out in permeabilized cells in the presence of cytosol prepared from MBSA-MDP-treated cells or untreated cells containing in vitro prenylated Rab proteins as described in the Materials and Methods. Cells were incubated for 60 minutes at 37°C to allow transport. Subsequently, formation of the bacteria biotin-avidin-HRP complex was measured to determine the transport of the Salmonella to lysosomes. Each point represents the mean±s.d. from three independent experiments, and these are expressed as relative units of transport to lysosomes.