TY - JOUR
T1 - Transcription of the oprF gene of pseudomonas aeruginosa is dependent mainly on the sigX sigma factor and is sucrose induced
AU - Bouffartigues, Emeline
AU - Gicquel, Gwendoline
AU - Bazire, Alexis
AU - Bains, Manjeet
AU - Maillot, Olivier
AU - Vieillard, Julien
AU - Feuilloley, Marc G.J.
AU - Orange, Nicole
AU - Hancock, R. E.W.
AU - Dufour, Alain
AU - Chevalier, Sylvie
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2012/8
Y1 - 2012/8
N2 - The OprF porin is the major outer membrane protein of Pseudomonas aeruginosa. OprF is involved in several crucial functions, including cell structure, outer membrane permeability, environmental sensing, and virulence. The oprF gene is preceded by the sigX gene, which encodes the poorly studied extracytoplasmic function (ECF) sigma factor SigX. Three oprF promoters were previously identified. Two intertwined promoters dependent on σ70 and SigX are located in the sigX-oprF intergenic region, whereas a promoter dependent on the ECF AlgU lies within the sigX gene. An additional promoter was found in the cmpX-sigX intergenic region. In this study, we dissected the contribution of each promoter region and of each sigma factor to oprF transcription using transcriptional fusions. In Luria-Bertani (LB) medium, the oprF-proximal region (sigX-oprF intergenic region) accounted for about 80% of the oprF transcription, whereas the AlgU-dependent promoter had marginal activity. Using the sigX mutant PAOSX, we observed that the SigX-dependent promoter was largely predominant over the σ70-dependent promoter. oprF transcription was increased in response to low NaCl or high sucrose concentrations, and this induced transcription was strongly impaired in the absence of SigX. The lack of OprF itself increased oprF transcription. Since these conditions led to cell wall alterations, oprF transcription could be activated by signals triggered by perturbation of the cell envelope.
AB - The OprF porin is the major outer membrane protein of Pseudomonas aeruginosa. OprF is involved in several crucial functions, including cell structure, outer membrane permeability, environmental sensing, and virulence. The oprF gene is preceded by the sigX gene, which encodes the poorly studied extracytoplasmic function (ECF) sigma factor SigX. Three oprF promoters were previously identified. Two intertwined promoters dependent on σ70 and SigX are located in the sigX-oprF intergenic region, whereas a promoter dependent on the ECF AlgU lies within the sigX gene. An additional promoter was found in the cmpX-sigX intergenic region. In this study, we dissected the contribution of each promoter region and of each sigma factor to oprF transcription using transcriptional fusions. In Luria-Bertani (LB) medium, the oprF-proximal region (sigX-oprF intergenic region) accounted for about 80% of the oprF transcription, whereas the AlgU-dependent promoter had marginal activity. Using the sigX mutant PAOSX, we observed that the SigX-dependent promoter was largely predominant over the σ70-dependent promoter. oprF transcription was increased in response to low NaCl or high sucrose concentrations, and this induced transcription was strongly impaired in the absence of SigX. The lack of OprF itself increased oprF transcription. Since these conditions led to cell wall alterations, oprF transcription could be activated by signals triggered by perturbation of the cell envelope.
UR - http://www.scopus.com/inward/record.url?scp=84866334456&partnerID=8YFLogxK
U2 - 10.1128/JB.00509-12
DO - 10.1128/JB.00509-12
M3 - Article
C2 - 22685281
AN - SCOPUS:84866334456
SN - 0021-9193
VL - 194
SP - 4301
EP - 4311
JO - Journal of Bacteriology
JF - Journal of Bacteriology
IS - 16
ER -