title: Quantitative proteomic analysis of Salmonella enterica serovar Typhimurium under PhoP/PhoQ activation conditions.
abstract: The PhoP/PhoQ two-component system plays a central regulatory role in the pathogenesis of Salmonella enterica serovar Typhimurium (S. Typhimurium), and it can be activated by low Mg(2+) concentrations and sublethal concentrations of cationic antimicrobial peptides (CAMP). Therefore, these two PhoP/PhoQ activation signals are considered as in vivo environmental cues sensed by S. Typhimurium for adaptation and survival. In this work, we conducted a SILAC (stable isotope labeling by amino acids in cell culture)-based quantitative proteomic study to survey the proteomic changes of S. Typhimurium in response to low Mg(2+) concentrations or CAMP. We discovered that CAMP activated a portion of the PhoP/PhoQ regulatory network, whereas low Mg(2+) concentrations upregulated nearly all known members of this network, a number of previously unknown proteins, and some proteins regulated by IHF and RpoS. Systematic analysis following metabolic pathways revealed that low Mg(2+) concentrations selectively influenced proteins of certain metabolic functions while CAMP did not. Our study indicates that the low Mg(2+)-concentration condition may lead S. Typhimurium into a growth-control lifestyle, which provides new perspectives about Salmonella's adaptation to the host environment.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, P. R. China.
authors.forename: Jian-Lan
authors.initials: JL
authors.lastname: Yu
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D015180:Electrophoresis, Gel, Two-Dimensional; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D006801:Humans; D034982:Integration Host Factors / Q000235:genetics / Q000378:metabolism; D007553:Isotope Labeling; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology*; D013058:Mass Spectrometry; D020543:Proteome / Q000737:chemistry / Q000235:genetics; D040901:Proteomics / Q000379:methods*; D012480:Salmonella Infections / Q000382:microbiology; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics*
chemical_list: D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D003470:Culture Media; D034982:Integration Host Factors; C079792:PhoQ protein, Bacteria; D020543:Proteome; D012808:Sigma Factor; C440508:integration host factor, Salmonella; C069567:sigma factor KatF protein, Bacteria; C061064:PhoP protein, Bacteria; D008274:Magnesium