Previously , a Salmonella enterica sero-var Typhimurium phoP locus mutant ( pho24 ) was isolated that constitutively expressed PhoP-activated genes ( pag ) and repressed PhoP-repressed genes ( prg ) ( 21 , 24 ) .
Expression of the phoP gene was not increased in intracellular bacteria , although we did observe the expected PhoPQ-regulated control of PhoP-activated genes ( pag ; examples include mgtBC and genes encoded by SPI2 ) and PhoP-repressed genes ( prg ; examples include genes encoded by SPI1 ) .
Moreover , the macB genes were expressed to higher levels in a phoP mutant than in Fig. 4A , suggesting that these genes are repressed by PhoP as low Mg2 .
Moreover , the macB genes were expressed to higher levels in a phoP mutant than in the wild-type strain , suggesting that these genes are repressed by PhoP as low Mg2 .
Moreover , the macA genes were expressed to higher levels in a phoP mutant than in Fig. 4A , suggesting that these genes are repressed by PhoP as low Mg2 .
Moreover , the macA genes were expressed to higher levels in a phoP mutant than in the wild-type strain , suggesting that these genes are repressed by PhoP as low Mg2 .
Inactivation of the phoP or levels of the PhoP-activated genes increased , phoQ genes renders Salmonella enterica serovar reached a peak .
The expression profile of phoP is rather consistent with the proposed role of PhoP as a repressor of SPI-1 genes since phoP was expressed when the SPI-1 regulators have become to decline .