Figure 6.
RegX3 is required for induction of ESX-5 protein secretion in response to phosphate limitation.
Wild-type M. tuberculosis Erdman (WT), ΔregX3, and ΔregX3 pNDregX3 strains were cultured for 5 days either in Sauton's complete medium without Tween-80 (control) or in Pi-free Sauton's medium without Tween-80 to which 2.5 μM KH2PO4 was added exogenously. 10 μg of cell lysate (CL) and 4 μg of culture filtrate (CF) proteins were subjected to SDS-PAGE and Western blot analysis. Anti-GroEL2 was used as both a loading control for the CL fraction and a cell lysis control in the CF fraction (data not shown). Anti-ModD was used as a loading control for the CF fraction. Results shown are representative of 3 independent experiments.