U.S. Department of Energy

Pacific Northwest National Laboratory

Top-down proteomics reveals a unique protein S-thiolation switch in Salmonella Typhimurium in response to infection-like conditions.

TitleTop-down proteomics reveals a unique protein S-thiolation switch in Salmonella Typhimurium in response to infection-like conditions.
Publication TypeJournal Article
Year of Publication2013
AuthorsAnsong C, Wu S, Meng D, Liu X, Brewer HM, Kaiser BLDeathera, Nakayasu ES, Cort JR, Pevzner P, Smith RD, Heffron F, Adkins JN, Pasa-Tolic L
JournalProc Natl Acad Sci U S A
KeywordsBacterial Proteins, Chromatography, Liquid, Cysteine, Dimerization, Humans, Mass Spectrometry, Protein Processing, Post-Translational, Protein Structure, Secondary, Protein Structure, Tertiary, Proteomics, Salmonella Infections, Salmonella typhimurium, Sulfur
Abstract

Characterization of the mature protein complement in cells is crucial for a better understanding of cellular processes on a systems-wide scale. Toward this end, we used single-dimension ultra-high-pressure liquid chromatography mass spectrometry to investigate the comprehensive "intact" proteome of the Gram-negative bacterial pathogen Salmonella Typhimurium. Top-down proteomics analysis revealed 563 unique proteins including 1,665 proteoforms generated by posttranslational modifications (PTMs), representing the largest microbial top-down dataset reported to date. We confirmed many previously recognized aspects of Salmonella biology and bacterial PTMs, and our analysis also revealed several additional biological insights. Of particular interest was differential utilization of the protein S-thiolation forms S-glutathionylation and S-cysteinylation in response to infection-like conditions versus basal conditions. This finding of a S-glutathionylation-to-S-cysteinylation switch in a condition-specific manner was corroborated by bottom-up proteomics data and further by changes in corresponding biosynthetic pathways under infection-like conditions and during actual infection of host cells. This differential utilization highlights underlying metabolic mechanisms that modulate changes in cellular signaling, and represents a report of S-cysteinylation in Gram-negative bacteria. Additionally, the functional relevance of these PTMs was supported by protein structure and gene deletion analyses. The demonstrated utility of our simple proteome-wide intact protein level measurement strategy for gaining biological insight should promote broader adoption and applications of top-down proteomics approaches.

DOI10.1073/pnas.1221210110
PubMed ID23720318
PubMed Central IDPMC3690903
Grant List5P41RR018522-10 / RR / NCRR NIH HHS / United States
8 P41 GM103493-10 / GM / NIGMS NIH HHS / United States
GM094623 / GM / NIGMS NIH HHS / United States
U01 GM094623 / GM / NIGMS NIH HHS / United States
Y01 AI008401 / AI / NIAID NIH HHS / United States
Y1-AI-8401 / AI / NIAID NIH HHS / United States
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