Unknown

Dataset Information

0

Pseudomonas aeruginosa AlgR represses the Rhl quorum-sensing system in a biofilm-specific manner.


ABSTRACT: AlgR controls numerous virulence factors in Pseudomonas aeruginosa, including alginate, hydrogen cyanide production, and type IV pilus-mediated twitching motility. In this study, the role of AlgR in biofilms was examined in continuous-flow and static biofilm assays. Strain PSL317 (DeltaalgR) produced one-third the biofilm biomass of wild-type strain PAO1. Complementation with algR, but not fimTU-pilVWXY1Y2E, restored PSL317 to the wild-type biofilm phenotype. Comparisons of the transcriptional profiles of biofilm-grown PAO1 and PSL317 revealed that a number of quorum-sensing genes were upregulated in the algR deletion strain. Measurement of rhlA::lacZ and rhlI::lacZ promoter fusions confirmed the transcriptional profiling data when PSL317 was grown as a biofilm, but not planktonically. Increased amounts of rhamnolipids and N-butyryl homoserine lactone were detected in the biofilm effluent but not the planktonic supernatants of the algR mutant. Additionally, AlgR specifically bound to the rhlA and rhlI promoters in mobility shift assays. Moreover, PAO1 containing a chromosomal mutated AlgR binding site in its rhlI promoter formed biofilms and produced increased amounts of rhamnolipids similarly to the algR deletion strain. These observations indicate that AlgR specifically represses the Rhl quorum-sensing system during biofilm growth and that such repression is necessary for normal biofilm development. These data also suggest that AlgR may control transcription in a contact-dependent or biofilm-specific manner.

SUBMITTER: Morici LA 

PROVIDER: S-EPMC2168728 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature

altmetric image

Publications

Pseudomonas aeruginosa AlgR represses the Rhl quorum-sensing system in a biofilm-specific manner.

Morici Lisa A LA   Carterson Alexander J AJ   Wagner Victoria E VE   Frisk Anders A   Schurr Jill R JR   Höner zu Bentrup Kerstin K   Hassett Daniel J DJ   Iglewski Barbara H BH   Sauer Karin K   Schurr Michael J MJ  

Journal of bacteriology 20070831 21


AlgR controls numerous virulence factors in Pseudomonas aeruginosa, including alginate, hydrogen cyanide production, and type IV pilus-mediated twitching motility. In this study, the role of AlgR in biofilms was examined in continuous-flow and static biofilm assays. Strain PSL317 (DeltaalgR) produced one-third the biofilm biomass of wild-type strain PAO1. Complementation with algR, but not fimTU-pilVWXY1Y2E, restored PSL317 to the wild-type biofilm phenotype. Comparisons of the transcriptional p  ...[more]

Similar Datasets

| S-EPMC2737955 | biostudies-literature
| S-EPMC3587504 | biostudies-literature
| S-EPMC4148453 | biostudies-literature
| S-EPMC7015896 | biostudies-literature
| S-EPMC7890550 | biostudies-literature
| S-EPMC3146268 | biostudies-literature
| S-EPMC3816427 | biostudies-literature
| S-EPMC2633808 | biostudies-other
| S-EPMC6664025 | biostudies-literature
| S-EPMC4345325 | biostudies-literature