The level of Yop proteins secreted by Yersinia enterocolitica is changed in maltose mutants

Abstract

Enteropathogenic Yersinia enterocolitica strains express a set of plasmid-encoded proteins called Yops, involved in pathogenicity. We studied the influence of the maltose system on the production of Yop proteins and found that the level of Yop proteins of Y. enterocolitica O:9 was reduced in the presence of maltose. Transposon insertion mutants impaired with the maltose transport activity showed a decreased level in the production of Yop proteins. The transcription of the yopH gene for YopH phosphatase in these maltose mutants was unchanged and revealed a maltose mutation impaired in the secretion of Yop proteins instead of their expression. ß

The osmotic regulator OmpR is involved in the response ofYersinia enterocoliticaO:9 to environmental stresses and survival within macrophages

“…The ampli¢ed PCR product was then cloned by blunt ends into a vector pBluescript II SK digested with SmaI and the resulting plasmid pYRM1 was transformed into E. coli Top10FP strain. Mating between the donor and recipient Y. enterocolitica Ye9 NS strain was performed on ¢lters, as previously described [25]. Plasmid DNA with the cloned ompR insert was subsequently used as a circular template for PCR.…”

“…The resulting construct designated pSYR22 was transformed into E. coli S17-1 Vpir. Mating between the donor and recipient Y. enterocolitica Ye9 NS strain was performed on ¢lters, as previously described [25]. The transconjugants were selected on LB plates with Ap, Km, and Nal antibiotics.…”

New tools for studying mal gene regulation in Yersinia pestis

“…Interestingly, while mal genes play a universal role in metabolism of maltose, these genes may also be related to virulence in other bacteria related to Y. pestis, including Vibrio cholerae and Yersinia enterocolitica (Lång et al, 1994;Brzostek and Raczkowska, 2001). In these studies, the addition of maltose to V. cholerae cultures inhibited the extracellular secretion of cholera toxin and soluble hemagglutinin-protease and increased the production of toxin-coregulated pilus (Lång et al, 1994).…”

“…Mutants of malF in V. cholerae were unable to synthesize or secrete cholera toxin (Lång et al, 1994). Also, exposing Y. enterocolitica to maltose decreased the production of Yop proteins, leading to the proposal that this effect was related to the interaction of the maltose transport system and the Yop secretion system (Brzostek and Raczkowska, 2001).…”