GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10447889

From GONUTS
Jump to: navigation, search
Citation

Beuzón, CR, Banks, G, Deiwick, J, Hensel, M and Holden, DW (1999) pH-dependent secretion of SseB, a product of the SPI-2 type III secretion system of Salmonella typhimurium. Mol. Microbiol. 33:806-16

Abstract

The type III secretion system of Salmonella pathogenicity island 2 (SPI-2) is required for bacterial replication inside macrophages. SseB has been considered a putative target of the secretion system on the basis of its similarity with EspA, a protein secreted by the type III secretion system of enteropathogenic Escherichia coli (EPEC). EspA forms a filamentous structure on the bacterial cell surface and is involved in translocation of proteins into the eukaryotic cytosol. In this paper, we show that SseB is a secreted protein that associates with the surface of the bacterial cell and might, therefore, also be required for delivery of SPI-2 effector proteins to the eukaryotic cell cytosol. SseB begins to accumulate inside the bacterial cell when the culture enters early stationary phase. However, SseB is only secreted if the bacteria are grown at low pH or if the pH is shifted after growth from 7.0 to below pH 5.0. The secretion occurs within minutes of acidification and is totally dependent on a functional SPI-2 type III secretion system. As the pH of the Salmonella-containing vacuole inside host cells has been shown to acidify to between pH 4.0 and 5.0, and as SPI-2 gene expression occurs inside host cells, low pH might be a physiological stimulus for SPI-2-mediated secretion in vivo.

Links

PubMed

Keywords

Agglutination Tests; Bacterial Proteins/metabolism; Cell Division; Endopeptidase K/metabolism; Escherichia coli; Escherichia coli Proteins; Genes, Reporter; Hydrogen-Ion Concentration; Membrane Proteins/metabolism; Mutation; Recombinant Proteins; Salmonella typhimurium/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

SALTY:SSEL

GO:0009405: pathogenesis

ECO:0000315:

P

SseL is required for a delayed cytotoxic effect in infected macrophages. (Figure 4)

complete


See also

References

See Help:References for how to manage references in GONUTS.