Fig 4.
Regulation of RNA T3S signals by Hfq. (A) Hfq-dependent translocation of the UTR::cyaA′ fusions. SpvD1–30::CyaA′ was a positive control to verify the functionality of the SPI-2 T3SS. (Left) Western blots showing CyaA′ expression from LB cultures. Samples were normalized to an OD600, and ∼105 bacteria were loaded into each lane. (Middle) UTR::cyaA′ fusions. (Right) Bacteria were induced for SPI-2 expression and used to infect J774 macrophages. Translocation was evaluated by cAMP ELISA. The ssaK mutant is a functional SPI-2 mutant. (B) Hfq-dependent translocation of intact S. Typhimurium 14028 effectors. Constructs were evaluated for expression and secretion into J774 macrophages as described above.