A novel promoter driving the expression of the quorum-sensing PqsE protein shows substantial differences in Pseudomonas aeruginosa and Pseudomonas paraeruginosa.
- 1Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad Universitaria CP 04510, Ciudad de México, Mexico
- 2Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Tercer Circuito Exterior, Ciudad Universitaria, CP 04510, Ciudad de México, Mexico
- 3Programa de Genómica Evolutiva, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, CP 62210, Mexico
Abstract
Pseudomonas aeruginosa is an important bacterial pathogen due to its production of different virulence factors, several of which, like rhamnolipids elastase and pyocyanin (PYO), are regulated by the quorum-sensing (QS) response, which is composed of three transcriptional regulators/autoinducer systems. At the top of the regulatory cascade is LasR/3-oxo-dodecanoyl homoserine lactone, which activates the expression of the RhlR/butanoyl homoserine lactone system and of PqsR. The latter, when coupled with its autoinducer 2-heptyl-3,4-dihydroxyquinoline (PQS), activates the transcription of the pqsABCDE operon, which encodes the enzymes responsible for the synthesis of 4-hydroxy-2-heptylquinoline which is the precursor of PQS. The Pqs system plays a key role in the production of PYO, mainly by regulating the expression of PqsE. The PqsE protein forms a protein complex with RhlR required to activate the transcription of the phz operons for PYO production. This hierarchical QS regulatory network is conserved in the recently described Pseudomonas paraeruginosa species, which produces the same virulence factors as P. aeruginosa. In this work, we characterize a promoter that is located directly upstream of pqsE in P. aeruginosa PAO1 and show that transcription from this promoter is repressed by the global regulator Vfr. By contrast, in P. paraeruginosa strains, whereas the -10 and -35 promoter sequences are conserved, the Vfr-binding site is not present, enabling the constitutive expression of the pqsE ORF independent of PqsR/PQS regulation. The implications for PYO production as a virulence-related trait in P. paraeruginosa are discussed.
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BibTeX
@article{montelongomartinez2026novel,
title = {{A novel promoter driving the expression of the quorum-sensing PqsE protein shows substantial differences in Pseudomonas aeruginosa and Pseudomonas paraeruginosa.}},
author = {Luis Fernando Montelongo-Martínez and Sara E. Quiroz-Morales and Miguel Cocotl-Yañez and Gloria Soberón-Chávez},
journal = {Microbiology (Reading, England)},
year = {2026},
month = oct,
doi = {10.1099/mic.0.001788},
url = {https://europepmc.org/article/MED/42949998},
note = {CC BY},
}
RIS
TY - JOUR
TI - A novel promoter driving the expression of the quorum-sensing PqsE protein shows substantial differences in Pseudomonas aeruginosa and Pseudomonas paraeruginosa.
AU - Luis Fernando Montelongo-Martínez
AU - Sara E. Quiroz-Morales
AU - Miguel Cocotl-Yañez
AU - Gloria Soberón-Chávez
PY - 2026
DA - 2026/10/01
JO - Microbiology (Reading, England)
DO - 10.1099/mic.0.001788
UR - https://europepmc.org/article/MED/42949998
AB - Pseudomonas aeruginosa is an important bacterial pathogen due to its production of different virulence factors, several of which, like rhamnolipids elastase and pyocyanin (PYO), are regulated by the quorum-sensing (QS) response, which is composed of three transcriptional regulators/autoinducer systems. At the top of the regulatory cascade is LasR/3-oxo-dodecanoyl homoserine lactone, which activates the expression of the RhlR/butanoyl homoserine lactone system and of PqsR. The latter, when coupled with its autoinducer 2-heptyl-3,4-dihydroxyquinoline (PQS), activates the transcription of the pqsABCDE operon, which encodes the enzymes responsible for the synthesis of 4-hydroxy-2-heptylquinoline which is the precursor of PQS. The Pqs system plays a key role in the production of PYO, mainly by regulating the expression of PqsE. The PqsE protein forms a protein complex with RhlR required to activate the transcription of the phz operons for PYO production. This hierarchical QS regulatory network is conserved in the recently described Pseudomonas paraeruginosa species, which produces the same virulence factors as P. aeruginosa. In this work, we characterize a promoter that is located directly upstream of pqsE in P. aeruginosa PAO1 and show that transcription from this promoter is repressed by the global regulator Vfr. By contrast, in P. paraeruginosa strains, whereas the -10 and -35 promoter sequences are conserved, the Vfr-binding site is not present, enabling the constitutive expression of the pqsE ORF independent of PqsR/PQS regulation. The implications for PYO production as a virulence-related trait in P. paraeruginosa are discussed.
SN - 1350-0872
SN - 1465-2080
ER -