SopB and SifA modify the proteome of the Salmonella-containing vacuole in the social amoeba Dictyostelium discoideum

ABSTRACT: Salmonella enterica serovar Typhimurium is a rod-shaped Gram-negative bacterium. It is a leading cause of gastroenteritis and public health problem. In the environment, it interacts with protozoa, particular amoeba, however the interactions between Salmonella and these eukaryotic microbes have not been addressed in detail. We and others recently described that S. Typhimurium is able to survive in the model amoeba Dictyostelium discoideum requiring the Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2, respectively)-encoded type three secretion systems (T3SSs). In this work, we investigated the role of two particular effector proteins, SopB and SifA that are secreted by either one of the T3SSs. SopB and SifA are involved in the remodelling of the intracellular compartment that contains Salmonella (Salmonella-containing vacuole, SCV) in other cellular models. We combined genetic and proteomics analysis to investigate the roles of SopB and SifA during infections of D. discoideum. We identified over 1,000 proteins per sample performing proteomics on fractions enriched in SCVs from amoeba cells infected with wild-type, sopB or sifA S. Typhimurium. Among them, we observed several Rho GTPases, guanine nucleotide exchange factors and motor proteins. Finally, we decided to evaluate if the changes observed in the proteome from the SCV of wild-type and mutants affect the intracellular survival of S. Typhimurium. These finding suggest that Salmonella exploits this route to survive intracellularly, a process that requires SopB and/or SifA effectors. To our knowledge this is the first proteomic description of the Salmonella intracellular compartment in D. discoideum.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Salmonella Typhimurium (strain 14028s / Sgsc 2262) Dictyostelium Discoideum (slime Mold)

SUBMITTER: Camila Valenzuela  

LAB HEAD: Carlos A. Santiviago

PROVIDER: PXD014955 | Pride | 2020-09-23

REPOSITORIES: Pride