Revision as of 07:50, 16 October 2018

Promoter sifA

Gene sifA locates in Salmonella pathogenicity island-2 (SPI-2) and has the function of maintaining the integrity of Salmonella-Containing Vacuole (SCV). Some studies was reported that expression of SifA is required for intracellular enviroment. In other words, promoter of sifA expresses SifA only when salmonella enter the host cells¹. A fragment including sifA promoter region and RBS region were amplified from Salmonella SL1344 genome. SipD is required for bacterial internalization. ΔsipD mutant can not enter host cells. Thus, we use this strain as a control. Microscopy suggests that only intracellular bacteria express eGFP which under the control of P_sifA (Figure 1).
Figure 1. Hela GSDMD KO cells respectively infected with the ΔsipD or ΔsifA mutant. These mutants contain a low copy number plasmid to express eGFP which was regulated by P_sifA.

Notice

Reference

1. Garmendia, J., Beuzon, C. R., Ruiz-Albert, J. & Holden, D. W. The roles of SsrA-SsrB and OmpR-EnvZ in the regulation of genes encoding the Salmonella typhimurium SPI-2 type III secretion system. Microbiology 149, 2385-2396, doi:10.1099/mic.0.26397-0 (2003).