Analysis of Salmonella PhoP/PhoQ regulation by dimethyl-SRM-based quantitative proteomics

Biochim Biophys Acta. 2016 Jan;1864(1):20-8. doi: 10.1016/j.bbapap.2015.10.003. Epub 2015 Oct 22.

Abstract

SRM (selected reaction monitoring), a tandem mass spectrometry-based method characterized by high repeatability and accuracy, is an effective tool for the quantification of predetermined proteins. In this study, we built a time-scheduled dimethyl-SRM method that can provide the precise relative quantification of 92 proteins in one run. By applying this method to the Salmonella PhoP/PhoQ two-component system, we found that the expression of selected PhoP/PhoQ-activated proteins in response to Mg(2+) concentrations could be divided into two distinct patterns. For the time-course SRM experiment, we found that the dynamics of the selected PhoP/PhoQ-activated proteins could be divided into three distinct patterns, providing a new clue regarding PhoP/PhoQ activation and regulation. Moreover, the results for iron homeostasis proteins in response to Mg(2+) concentrations revealed that the PhoP/PhoQ two-component system may serve as a repressor for iron uptake proteins. And ribosomal protein levels clearly showed a response to different Mg(2+) concentrations and to time.

Keywords: Mg(2+) concentrations; SRM; Salmonella PhoP/PhoQ; Time course.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism*
  • Blotting, Western
  • Computational Biology / methods*
  • Dose-Response Relationship, Drug
  • Magnesium / pharmacology
  • Peptides / metabolism
  • Protein Interaction Maps / drug effects
  • Proteome / metabolism
  • Proteomics / methods*
  • Salmonella / metabolism*
  • Tandem Mass Spectrometry / methods*
  • Time Factors

Substances

  • Bacterial Proteins
  • Peptides
  • PhoQ protein, Bacteria
  • Proteome
  • PhoP protein, Bacteria
  • Magnesium