FIG 2.

PinT downregulates SPI1 expression by repressing hilA and rtsA translation. (A to C) β-Galactosidase activity in Salmonella strains containing an hilA′-′lacZ (A), hilD′-′lacZ (B), or rtsA′-′lacZ (C) translational fusion and plasmids overexpressing PinT grown under SPI1-inducing conditions. (D to F) β-Galactosidase activity in E. coli strains containing a P_BAD-hilA′-′lacZ (D), P_BAD-hilC′-′lacZ (E), or P_BAD-rtsA′-′lacZ (F) translational fusion and plasmids overexpressing PinT grown in the presence of 100 μM IPTG and 0.001% arabinose to induce sRNA expression and fusion expression, respectively. β-Galactosidase activity units are defined as (μmol of ONP formed min⁻¹) × 10⁶/(OD₆₀₀ × ml of cell suspension) and are reported as mean ± standard deviation, where n = 3. P values (unpaired t test) are indicated as follows: **, P < 0.01; ***, P < 0.001; n.s., not significant. The strains used were JS892, JS2333, JS2334, JMS6503, JMS6504, and JMS6505, each with plasmid pBRplac or pPinT.