The omp50 gene is transcriptionally controlled by a temperature-dependent mechanism conserved among thermophilic Campylobacter species.
The thermophilic Campylobacters are enteropathogenic for humans. We recently showed that Omp50 is a Campylobacter species-specific porin produced in Campylobacter jejuni and Campylobacter lari but not in Campylobacter coli. In the present study, we investigated regulation of the omp50 gene and found that its expression in C. jejuni was temperature-dependent, but independent of growth phase or medium viscosity. The use of RT-PCR and omp50::lacZ fusions showed that growth temperature control occurred at the transcriptional level. The promoter and the coding sequence were cloned in an Escherichia coli-Campylobacter shuttle plasmid and transferred to E. coli and to a C. jejuni Omp50-deficient strain. Regulation of omp50 gene expression by growth temperature was observed in the recombinant C. jejuni strain, but not in E. coli. The same regulation was also observed in wild-type C. lari strains and in a C. coli strain supplemented by the plasmid, suggesting that omp50 expression is controlled by a mechanism conserved among Campylobacter species.
Dedieu
Luc
L
UMR-MD-1, IFR 48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, Marseille Cedex 5, France.
Pagès
Jean-Marie
JM
Bolla
Jean-Michel
JM
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002167:Campylobacter / Q000235:genetics* / Q000378:metabolism; D016123:Campylobacter jejuni / Q000235:genetics / Q000378:metabolism; D044863:Campylobacter lari / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D005822:Genetic Vectors / Q000235:genetics; D018272:Porins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D013696:Temperature; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D018272:Porins