Identification of FleQ from Pseudomonas aeruginosa as a c-di-GMP-responsive transcription factor

By J. W. Hickman, Caroline S Harwood. Molecular Microbiology, 2008

665 citations recorded by the source corpus.

High levels of the intracellular signalling molecule cyclic diguanylate (c‐di‐GMP) supress motility and activate exopolysaccharide (EPS) production in a variety of bacterial species. In many bacteria part of the effect of c‐di‐GMP is on gene expression, but the mechanism involved is not known for any species. We have identified the protein FleQ as a c‐di‐GMP‐responsive transcriptional regulator in Pseudomonas aeruginosa. FleQ is known to activate expression of flagella biosynthesis genes. Here we show that it also represses transcription of genes including the pel operon involved in EPS biosynthesis, and that this repression is relieved by c‐di‐GMP. Our in vivo data indicate that FleQ represses pel transcription and that pel transcription is not repressed when intracellular c‐di‐GMP levels are high. FleN, a known antiactivator of FleQ also participates in control of pel expression. In in vitro experiments we found that FleQ binds to pel promoter DNA and that this binding is inhibited by c‐di‐GMP. FleQ binds radiolabelled c‐di‐GMP in vitro. FleQ does not have amino acid motifs that resemble previously defined c‐di‐GMP binding domains. Our results show that FleQ is a new type of c‐di‐GMP binding protein that controls the transcriptional regulation of EPS biosynthesis genes in P. aeruginosa.

Subfields: Ecology, Genetics, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/307b58f30b398adce07c594605b68903b422f85a

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In Ecology

1. Bernd H. A. Rehm
2. Christopher J Jones
3. D. Wozniak
4. D. Limoli

In Genetics

1. Bernd H. A. Rehm
2. Christopher J Jones
3. D. Wozniak
4. D. Limoli

In Molecular Biology

1. Bernd H. A. Rehm
2. Minh Thu Tran Thi
3. David Wibowo
4. Christopher J Jones
5. D. Wozniak
6. D. Limoli

Citations in the corpus

• The Multiple Signaling Systems Regulating Virulence in Pseudomonas aeruginosa (2012, background): “aeruginosa, FleQ, has also been found to be c-di-GMP responsive, despite the absence of GGDEF, EAL, or any other known degenerate domains (87).”
• Pseudomonas aeruginosa Biofilms (2020, background): “The restricted flagellar movement has been implicated in mediating twitching motility and biosynthesis of exopolysaccharides required for surface association [56].”
• Bacterial Extracellular Polysaccharides in Biofilm Formation and Function (2015, background): “The fi rst of these regulatory pathways to be described was the regulation of the psl operon by the master fl agellum regulator, FleQ (56, 57).”