The Gac/Rsm and cyclic‐di‐GMP signalling networks coordinately regulate iron uptake in Pseudomonas aeruginosa. (25th June 2013)

• Record Type: Journal Article
• Authors: Frangipani, Emanuela; Visaggio, Daniela; Heeb, Stephan; Kaever, Volkhard; Cámara, Miguel; Visca, Paolo; Imperi, Francesco
• Is Part Of: Environmental microbiology. Volume 16:Number 3(2014:Mar.)
• Page Start: 676
• Page End: 688
• Publication Date: 2013-06-25
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12164
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p> <italic>Pseudomonas aeruginosa</italic> is a versatile bacterial pathogen capable of occupying diverse ecological niches. To cope with iron limitation, <italic>P. aeruginosa</italic> secretes two siderophores, pyoverdine and pyochelin, whose ability to deliver iron to the cell is crucial for biofilm formation and pathogenicity. In this study, we describe a link between iron uptake and the Gac/Rsm system, a conserved signal transducing pathway of <italic>P. aeruginosa</italic> that controls the production of extracellular products and virulence factors, as well as the switch from planktonic to biofilm lifestyle. We have observed that pyoverdine and pyochelin production in <italic>P. aeruginosa</italic> is strongly dependent on the activation state of the Gac/Rsm pathway, which controls siderophore regulatory and biosynthetic genes at the transcriptional level, in a manner that does not involve regulation of ferric uptake regulator (Fur) expression. Gac/Rsm‐mediated regulation of iron uptake genes appears to be conserved in different <italic>P. aeruginosa</italic> strains. Further experiments led to propose that the Gac/Rsm system regulates siderophore production through modulation of the intracellular levels of the second messenger c‐di‐GMP, indicating that the c‐di‐GMP and the Gac/Rsm regulatory networks essential for biofilm formation can also coordinately control iron uptake in <italic>P. aeruginosa</italic>.</p> </abstract>