FIG 2.
The presence of EspZ in host cells can limit T3SS-dependent effector translocation. A TEM-1 β-lactamase (encoded on pSR1) reporter system was used to monitor effector translocation from WT REPEC into host cells transiently transfected with an REPEC espZ-containing (pSR2), EPEC espZ-containing (pSR3), or control (pSR4) plasmid (A) or previously infected (first wave) with WT REPEC, the REPEC ΔespZ mutant, or the REPEC ΔespZ mutant complemented with REPEC EspZ (espZ/espZR) or EPEC EspZ (espZ/espZE) (B). TEM-1 β-lactamase translocation-dependent cleavage of the β-lactam-containing compound CCF2 in host cells was monitored via fluorescence measurements over a 120-min time period. Asterisks indicate significant differences (P ≤ 0.05).