FIG 7 .
Dysfunctional versions of EscR have no dominant negative effect and cannot be rescued by insertion of an aspartic acid residue into the TMD sequence. (A) Protein secretion profiles of WT and ΔescR EPEC strains transformed with EscRWT-3HA, EscR-TM3ex-3HA, or EscRD171A-3HA grown under T3SS-inducing conditions. The secreted fractions were treated and analyzed as described in the Fig. 1A legend. The expression of EscR-3HA variants was examined by analyzing the bacterial pellets by SDS-PAGE and Western blot analysis with an anti-HA antibody. Numbers at left are molecular masses in kilodaltons. (B) Protein secretion profiles of ΔescR EPEC transformed with EscRWT-3HA, EscR-TM3ex-3HA, or EscRTM3exD171-3HA grown under T3SS-inducing conditions. The secreted fractions were treated and analyzed as described in the Fig. 1A legend. The expression of EscR-3HA variants was examined by analyzing the bacterial pellets by SDS-PAGE and Western blot analysis with an anti-HA antibody.