OmpR negatively regulates expression of invasin in Yersinia enterocolitica.
Invasin, the major adhesion and invasion factor of Yersinia enterocolitica, is encoded by the inv gene, which is regulated by growth phase and in response to a variety of environmental conditions such as temperature, pH and osmolarity. So far, three proteins, RovA, H-NS and YmoA, have been identified as factors regulating the expression of the inv gene in enteropathogenic Yersinia. Here, data from inv' : : lacZYA chromosomal gene fusion studies are presented indicating that OmpR, the response regulator of the EnvZ/OmpR two-component system, acts to negatively regulate inv expression at the transcriptional level at 25 degrees C, and that high osmolarity enhances the inhibitory effect of this protein. In a strain lacking OmpR the expression of inv at 25 degrees C was increased sixfold, but at 37 degrees C, a temperature known to repress inv expression, this effect was not observed, suggesting that temperature regulation of inv is OmpR-independent. Furthermore, the expression of inv in the ompR background was no longer responsive to increased osmolarity. Complementation with the active ompR allele restored wild-type inv expression in the ompR mutant. In silico analysis of the Y. enterocolitica O : 9 inv promoter sequence revealed the presence of an OmpR consensus binding site located in the -15 to -33 region. OmpR was able to specifically bind to a fragment of the inv promoter containing this putative binding site in electrophoretic mobility shift assays. Thus, OmpR seems to be a repressor of inv in Y. enterocolitica.
Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1, 02-096 Warsaw, Poland.
Katarzyna
K
Brzostek
Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1, 02-096 Warsaw, Poland.
Marta
M
Brzóstkowska
Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1, 02-096 Warsaw, Poland.
Iwona
I
Bukowska
Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1, 02-096 Warsaw, Poland.
Ewa
E
Karwicka
Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1, 02-096 Warsaw, Poland.
Adrianna
A
Raczkowska
D018829:Adhesins, Bacterial / Q000235:genetics*; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D009994:Osmolar Concentration; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013696:Temperature; D015534:Trans-Activators / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic; D015008:Yersinia enterocolitica / Q000235:genetics*; D001616:beta-Galactosidase / Q000032:analysis
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D015534:Trans-Activators; C112177:osmolarity response regulator proteins; C053476:invasin, Yersinia; D001616:beta-Galactosidase