Distinct temporal expression of PhoP-activated genes in response to mildly acidic pH and low Mg2 + We examined the mRNA levels of the PhoP-activated genes pagC and pagK at 2 h and 4 h after Salmonella was shifted from non-inducing conditions for the PhoQ protein to media containing either mildly acidic pH or low ( i.e. , 10 μM ) Mg2 + .
Distinct temporal expression of PhoP-activated genes in response to mildly acidic pH and low Mg2 + he MgtA protein is necessary for full transcription of a subset of PhoP-activated genes hen the PhoQ inducing signal is low Mg2 + T w Wild-type and mgtA strains had similar pagC and pagK mRNA levels at 2 h post induction ( Fig. 2A ) ( i.e. , ratio of wild-type/mgtA of 1 ) .