Figure 1
SodC and SodC-F differential accumulation. Panel A: Kinetics of accumulation of SodC and SodC-F2 proteins in vitro cultures. Overnight bacterial culture of strain RG-F111 was diluted 1:500 in LB medium (time zero) and grown at 37°C under aerobic conditions. Aliquots were withdrawn at the different times: 2 h (lane 1), 3 h (lane 2), 4 h (lane 3), 24 h (lane 4), and 48 h (lane 5). Cells were harvested, lysed and the samples (approximately 5 × 107 CFU lane-1) were loaded in a 15% SDS-PAGE and processed for the detection of epitope-tagged proteins as described in methods. Panel B: Effects of oxygen and temperature on SodC and SodC-F2 intracellular accumulation. Strain RG-F111 was grown for 24 h at 37°C (lanes 1 and 2) or at 25°C (lane 3) in presence (lanes 2 and 3) or absence of oxygen (lane 1) The samples were prepared as described above. Panel C:Variations in SodC and SodC-F2 relative abundance in infected Caco-2 cells. Strain RG-F111 was grown overnight in LB medium (lane 1) and adherent (lane 2) or intracellular (lane 3) bacteria were harvested from Caco-2 cells 5h post-infection. Approximately equal numbers of bacteria were loaded in each lane. A densitometric analysis of the western blot carried out with the Gel-Pro Analyzer software (Media Cybernetics) is reported in the graph. White bar, SodC; black bar, SodC-F2.