InvB is a type III secretion-associated chaperone for the Salmonella enterica effector protein SopE.
SopE is a bacteriophage-encoded effector protein of Salmonella enterica serovar Typhimurium that is translocated into the cytosol of eukaryotic cells by a type III secretion system (TTSS) (W.-D. Hardt, H. Urlaub, and J. E. Galán, Proc. Natl. Acad. Sci. USA 95:2574-2579, 1998; M. W. Wood, R. Rosqvist, P. B. Mullan, M. H. Edwards, and E. E. Galyov, Mol. Microbiol. 22:327-338, 1996). In this study, we provide evidence that an unlinked gene carried within the Salmonella pathogenicity island 1 (SPI-1), invB (K. Eichelberg, C. Ginocchio, and J. E. Galán, J. Bacteriol. 176:4501-4510, 1994), is required for the secretion of SopE through the SPI-1 TTSS. Furthermore, far-Western blotting analysis shows that SopE directly interacts with InvB through a domain located at its amino terminus. We conclude that InvB is the TTSS-associated chaperone for SopE.
Lee
Sang Ho
SH
Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, USA.
Galán
Jorge E
JE
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D007763:Lac Operon; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D019779:Salmonella enterica / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D018832:Molecular Chaperones; C103987:SopE protein, Salmonella; C088597:invB protein, Salmonella