Systems-Level Overview of Host Protein Phosphorylation During Shigella flexneri Infection Revealed by Phosphoproteomics

• Published in: Molecular & cellular proteomics Vol. 12; no. 10; pp. 2952 - 2968
• Main Authors: Schmutz, Christoph, Ahrné, Erik, Kasper, Christoph A., Tschon, Therese, Sorg, Isabel, Dreier, Roland F., Schmidt, Alexander, Arrieumerlou, Cécile
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2013; The American Society for Biochemistry and Molecular Biology
• Subjects: Animals; Bacterial Proteins - metabolism; Cell Line; Dysentery, Bacillary - metabolism; HeLa Cells; Host-Pathogen Interactions - physiology; Humans; Mice; Phosphoproteins - metabolism; Phosphorylation; Proteomics - methods; Salmonella; Salmonella typhi - metabolism; Shigella flexneri; Shigella flexneri - physiology
• ISSN: 1535-9476; 1535-9484
• DOI: 10.1074/mcp.M113.029918

The enteroinvasive bacterium Shigella flexneri invades the intestinal epithelium of humans. During infection, several injected effector proteins promote bacterial internalization, and interfere with multiple host cell responses. To obtain a systems-level overview of host signaling during infection, we analyzed the global dynamics of protein phosphorylation by liquid chromatography-tandem MS and identified several hundred of proteins undergoing a phosphorylation change during the first hours of infection. Functional bioinformatic analysis revealed that they were mostly related to the cytoskeleton, transcription, signal transduction, and cell cycle. Fuzzy c-means clustering identified six temporal profiles of phosphorylation and a functional module composed of ATM-phosphorylated proteins related to genotoxic stress. Pathway enrichment analysis defined mTOR as the most overrepresented pathway. We showed that mTOR complex 1 and 2 were required for S6 kinase and AKT activation, respectively. Comparison with a published phosphoproteome of Salmonella typhimurium-infected cells revealed a large subset of coregulated phosphoproteins. Finally, we showed that S. flexneri effector OspF affected the phosphorylation of several hundred proteins, thereby demonstrating the wide-reaching impact of a single bacterial effector on the host signaling network.