Synergistic action of SPI-1 gene expression in Salmonella enterica serovar typhimurium through transcriptional crosstalk with the flagellar system.

Autor: Hamed S; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL, 61801, USA.; Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University - Ain Helwan, Helwan, 11795, Egypt., Wang X; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL, 61801, USA., Shawky RM; Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University - Ain Helwan, Helwan, 11795, Egypt., Emara M; Department of Microbiology and Immunology, Faculty of Pharmacy, Helwan University - Ain Helwan, Helwan, 11795, Egypt., Aldridge PD; Institute of Cell & Molecular Biosciences, Faculty Medical Sciences, Newcastle University, Newcastle upon Tyne, UK., Rao CV; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL, 61801, USA. cvrao@illinois.edu.
Jazyk: angličtina
Zdroj: BMC microbiology [BMC Microbiol] 2019 Sep 05; Vol. 19 (1), pp. 211. Date of Electronic Publication: 2019 Sep 05.
DOI: 10.1186/s12866-019-1583-7
Abstrakt: Background: Salmonella enterica serovar Typhimurium is a common food-borne pathogen. S. enterica uses a type III secretion system encoded within Salmonella pathogenicity island 1 (SPI-1) to invade intestinal epithelial cells. A complex network of interacting transcription factors regulates SPI-1 gene expression. In addition, SPI-1 gene expression is coupled to flagellar gene expression. Both SPI-1 and flagellar gene expression are bistable, with co-existing populations of cells expressing and not expressing these genes. Previous work demonstrated that nutrients could be used to tune the fraction of cells expressing the flagellar genes. In the present study, we tested whether nutrients could also tune the fraction of cells expressing the SPI-1 genes through transcriptional crosstalk with the flagellar genes.
Results: Nutrients alone were not found to induce SPI-1 gene expression. However, when the cells were also grown in the presence of acetate, the concentration of nutrients in the growth medium was able to tune the fraction of cells expressing the SPI-1 genes. During growth in nutrient-poor medium, acetate alone was unable to induce SPI-1 gene expression. These results demonstrate that acetate and nutrients synergistically activate SPI-1 gene expression. The response to acetate was governed by the BarA/SirA two-component system and the response to nutrients was governed by transcriptional crosstalk with the flagella system, specifically through the action of the flagellar regulator FliZ.
Conclusions: Acetate and nutrients are capable of synergistically activating SPI-1 gene expression. In addition, these signals were found to tune the fraction of cells expressing the SPI-1 genes. The governing mechanism involves transcriptional crosstalk with the flagellar gene network. Collectively, these results further our understanding of SPI-1 gene regulation and provide the basis for future studies investigating this complex regulatory mechanism.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje