TY - JOUR
T1 - The OpdQ porin of Pseudomonas aeruginosa is regulated by environmental signals associated with cystic fibrosis including nitrate-induced regulation involving the NarXL two-component system
AU - Fowler, Randal C.
AU - Hanson, Nancy D.
N1 - Funding Information:
The authors thank Benoit Polack and Mary Lidstrom for providing the pEX100Tlink, pUCGmlox, pCM157 vectors. We also acknowledge the National Institutes of Health grant # P30 DK089507 for strain PW7548. We are grateful to the Creighton University School of Medicine for providing the funds to purchase a hypoxic chamber. This study was funded in part by research grants from the Streck, Inc. and Diatherix Laboratories, Inc.
Publisher Copyright:
© 2015 Published by John Wiley & Sons Ltd.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - Pseudomonas aeruginosa is a versatile opportunistic pathogen that causes chronic infections in immunocompromised hosts. Multiple porins modulate outer membrane permeability under various environmental conditions. The lung environment of cystic fibrosis (CF) patients is unique with changes occurring in nutrient availability, osmolarity, and oxygen content. Although P. aeruginosa gene expression is modified under these conditions, little is known about how they influence porin regulation. In this study, we evaluated the regulation of the outer membrane porin OpdQ, a member of the OprD family of porins, with regard to oxygen, nitrate, and/or NaCl levels. We demonstrated using promoter::fusion clones of P. aeruginosa PAO1 and clinical strains collected from CF patients that OpdQ was transcriptionally repressed under low oxygen but increased in the presence of nitrate. The nitrate-induced regulation of OpdQ was found to be dependent on the transcription factor NarL via the NarXL two-component system. In addition, NaCl-induced osmotic stress increased OpdQ production among most of the clinical strains evaluated. In conclusion, these data identify for the first time that specific environmental cues associated with the CF microenvironment influence porin regulation, and that the nitrate-induced regulation of OpdQ is associated with nitrate metabolism via the NarXL two-component system of P. aeruginosa. Pseudomonas aeruginosa is a versatile opportunistic pathogen capable of causing a variety of severe and chronic infections in immunocompromised hosts. In this study, we show that the regulation of the outer membrane porin OpdQ, a member of the OprD family of porins, is dependent on oxygen, nitrate, and/or NaCl levels. Our results indicate for the first time that specific environmental signals effect porin regulation, and that the nitrate-induced regulation of OpdQ is associated with nitrate metabolism via the NarXL two-component system in P. aeruginosa.
AB - Pseudomonas aeruginosa is a versatile opportunistic pathogen that causes chronic infections in immunocompromised hosts. Multiple porins modulate outer membrane permeability under various environmental conditions. The lung environment of cystic fibrosis (CF) patients is unique with changes occurring in nutrient availability, osmolarity, and oxygen content. Although P. aeruginosa gene expression is modified under these conditions, little is known about how they influence porin regulation. In this study, we evaluated the regulation of the outer membrane porin OpdQ, a member of the OprD family of porins, with regard to oxygen, nitrate, and/or NaCl levels. We demonstrated using promoter::fusion clones of P. aeruginosa PAO1 and clinical strains collected from CF patients that OpdQ was transcriptionally repressed under low oxygen but increased in the presence of nitrate. The nitrate-induced regulation of OpdQ was found to be dependent on the transcription factor NarL via the NarXL two-component system. In addition, NaCl-induced osmotic stress increased OpdQ production among most of the clinical strains evaluated. In conclusion, these data identify for the first time that specific environmental cues associated with the CF microenvironment influence porin regulation, and that the nitrate-induced regulation of OpdQ is associated with nitrate metabolism via the NarXL two-component system of P. aeruginosa. Pseudomonas aeruginosa is a versatile opportunistic pathogen capable of causing a variety of severe and chronic infections in immunocompromised hosts. In this study, we show that the regulation of the outer membrane porin OpdQ, a member of the OprD family of porins, is dependent on oxygen, nitrate, and/or NaCl levels. Our results indicate for the first time that specific environmental signals effect porin regulation, and that the nitrate-induced regulation of OpdQ is associated with nitrate metabolism via the NarXL two-component system in P. aeruginosa.
UR - http://www.scopus.com/inward/record.url?scp=84954394900&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84954394900&partnerID=8YFLogxK
U2 - 10.1002/mbo3.305
DO - 10.1002/mbo3.305
M3 - Article
C2 - 26459101
AN - SCOPUS:84954394900
SN - 2045-8827
VL - 4
SP - 967
EP - 982
JO - MicrobiologyOpen
JF - MicrobiologyOpen
IS - 6
ER -