title: Systems-level overview of host protein phosphorylation during Shigella flexneri infection revealed by phosphoproteomics.
abstract: 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.
authors.affiliation: Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmutz
authors.forename: Erik
authors.initials: E
authors.lastname: Ahrné
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Kasper
authors.forename: Therese
authors.initials: T
authors.lastname: Tschon
authors.forename: Isabel
authors.initials: I
authors.lastname: Sorg
authors.forename: Roland F
authors.initials: RF
authors.lastname: Dreier
authors.forename: Alexander
authors.initials: A
authors.lastname: Schmidt
authors.forename: Cécile
authors.initials: C
authors.lastname: Arrieumerlou
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D002460:Cell Line; D004405:Dysentery, Bacillary / Q000378:metabolism*; D006367:HeLa Cells; D054884:Host-Pathogen Interactions / Q000502:physiology*; D006801:Humans; D051379:Mice; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D040901:Proteomics / Q000379:methods; D012485:Salmonella typhi / Q000378:metabolism; D012763:Shigella flexneri / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D010750:Phosphoproteins