The Pseudomonas aeruginosa PsrA responds to long-chain fatty acid signals to regulate the fadBA5 β-oxidation operon

Kang, Yun; Nguyen, D.T.; Son, Mike S.; Hoang, Tung T.

doi:10.1099/mic.0.2008/018135-0

Cited by 89 publications

(125 citation statements)

References 39 publications

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“…That candidate PsrA site in P. aeruginosa coincides with the experimentally identified PsrA site (19). Recently, PsrA was shown to bind to the fadBA (PA3014-PA3013) operon promoter region (17). The transcriptome analysis also revealed a PsrA-dependent repression of acdH, etfBA, etf, psrA, PA1830, and other genes (17) for which PsrA binding sites were identified here (see Table S5 in the supplemental material).…”

Section: Vol 191 2009 Comparative Genomics Of Fa and Ilv Degradatiomentioning

confidence: 78%

Comparative Genomics of Regulation of Fatty Acid and Branched-Chain Amino Acid Utilization in Proteobacteria

et al. 2009

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Bacteria can use branched-chain amino acids (ILV, i.e., isoleucine, leucine, valine) and fatty acids (FAs) as sole carbon and energy sources converting ILV into acetyl-coenzyme A (CoA), propanoyl-CoA, and propionylCoA, respectively. In this work, we used the comparative genomic approach to identify candidate transcriptional factors and DNA motifs that control ILV and FA utilization pathways in proteobacteria. The metabolic regulons were characterized based on the identification and comparison of candidate transcription factor binding sites in groups of phylogenetically related genomes. The reconstructed ILV/FA regulatory network demonstrates considerable variability and involves six transcriptional factors from the MerR, TetR, and GntR families binding to 11 distinct DNA motifs. The ILV degradation genes in gamma-and betaproteobacteria are regulated mainly by a novel regulator from the MerR family (e.g., LiuR in Pseudomonas aeruginosa) (40 species); in addition, the TetR-type regulator LiuQ was identified in some betaproteobacteria (eight species). Besides the core set of ILV utilization genes, the LiuR regulon in some lineages is expanded to include genes from other metabolic pathways, such as the glyoxylate shunt and glutamate synthase in Shewanella species. The FA degradation genes are controlled by four regulators including FadR in gammaproteobacteria (34 species), PsrA in gamma-and betaproteobacteria (45 species), FadP in betaproteobacteria (14 species), and LiuR orthologs in alphaproteobacteria (22 species). The remarkable variability of the regulatory systems associated with the FA degradation pathway is discussed from functional and evolutionary points of view.Proteobacteria comprise one of the largest divisions within prokaryotes and incorporate species possessing a very complex collection of phenotypic and physiological attributes including many phototrophs, heterotrophs, and chemolithotrophs. The proteobacterial group is of great biological significance, as it includes a large number of pathogens and symbionts of animals and plants. Thus, proteobacteria display an amazing versatility in their abilities to use various carbon sources such as carbohydrates, nucleotides, amino acids, and lipids. The degradation of branched-chain amino acids valine, leucine, and isoleucine (ILV) and fatty acids (FAs) is used for ATP and energy production by many proteobacteria.The ILV degradation pathways are outlined in Fig. 1A. The first reaction is transamination to the corresponding ␣-keto acids using either branched-chain amino acid aminotransferase or leucine dehydrogenase. The second step is oxidative decarboxylation to the corresponding acyl-coenzyme A (CoA) derivative coupled to dehydrogenation, which is carried out by a common branched-chain ␣-keto acid dehydrogenase (BCDH) (EC 1.2.4.4) complex. The further conversion of branchedchain acyl-CoA derivatives of ILV amino acids, namely, isovaleryl-CoA for leucine, 2-methylbutanoyl-CoA for isoleucine, and isobutyryl-CoA for valine, into acetyl-CoA and propionyl-CoA is...

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Section: Vol 191 2009 Comparative Genomics Of Fa and Ilv Degradatiomentioning

confidence: 78%

Comparative Genomics of Regulation of Fatty Acid and Branched-Chain Amino Acid Utilization in Proteobacteria

et al. 2009

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“…PlcH activity also releases diacylglycerol, which can be oxidized by P. aeruginosa as a source of energy in the lung (19). Interestingly, the psrA transcript, which encodes a repressor of genes involved in the oxidation of lipids, was 12-fold more abundant in the WT than in the ⌬plcHR mutant (47). Fatty acid oxidation-associated transcripts (fad genes) were not among those identified as being different among the WT, ⌬plcHR, and ⌬gbdR strains.…”

Section: Resultsmentioning

confidence: 94%

Anr and Its Activation by PlcH Activity in Pseudomonas aeruginosa Host Colonization and Virulence

et al. 2013

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bPseudomonas aeruginosa hemolytic phospholipase C (PlcH) degrades phosphatidylcholine (PC), an abundant lipid in cell membranes and lung surfactant. A ⌬plcHR mutant, known to be defective in virulence in animal models, was less able to colonize epithelial cell monolayers and was defective in biofilm formation on plastic when grown in lung surfactant. Microarray analyses found that strains defective in PlcH production had lower levels of Anr-regulated transcripts than the wild type. PC degradation stimulated the Anr regulon in an Anr-dependent manner under conditions where Anr activity was submaximal because of the presence of oxygen. Two PC catabolites, choline and glycine betaine (GB), were sufficient to stimulate Anr activity, and their catabolism was required for Anr activation. The addition of choline or GB to glucose-containing medium did not alter Anr protein levels, growth rates, or respiratory activity, and Anr activation could not be attributed to the osmoprotectant functions of GB. The ⌬anr mutant was defective in virulence in a mouse pneumonia model. Several lines of evidence indicate that Anr is important for the colonization of biotic and abiotic surfaces in both P. aeruginosa PAO1 and PA14 and that increases in Anr activity resulted in enhanced biofilm formation. Our data suggest that PlcH activity promotes Anr activity in oxic environments and that Anr activity contributes to virulence, even in the acute infection phase, where low oxygen tensions are not expected. This finding highlights the relationships among in vivo bacterial metabolism, the activity of the oxygen-sensitive regulator Anr, and virulence.

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“…PsrA from P. aeruginosa responds to long-chain fatty acids to control expression of fad genes (163). In addition, PsrA plays a role in resistance to cationic antimicrobial peptides, antibiotic production, quorum sensing, and virulence, indicating that PsrA and long-chain fatty acids play an important role in the physiology of this important opportunistic pathogen.…”

Section: Tfrs and Lipid Metabolismmentioning

confidence: 99%

The TetR Family of Regulators

Cuthbertson

Nodwell

2013

Microbiol Mol Biol Rev

480

519

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SUMMARY The most common prokaryotic signal transduction mechanisms are the one-component systems in which a single polypeptide contains both a sensory domain and a DNA-binding domain. Among the >20 classes of one-component systems, the TetR family of regulators (TFRs) are widely associated with antibiotic resistance and the regulation of genes encoding small-molecule exporters. However, TFRs play a much broader role, controlling genes involved in metabolism, antibiotic production, quorum sensing, and many other aspects of prokaryotic physiology. There are several well-established model systems for understanding these important proteins, and structural studies have begun to unveil the mechanisms by which they bind DNA and recognize small-molecule ligands. The sequences for more than 200,000 TFRs are available in the public databases, and genomics studies are identifying their target genes. Three-dimensional structures have been solved for close to 200 TFRs. Comparison of these structures reveals a common overall architecture of nine conserved α helices. The most important open question concerning TFR biology is the nature and diversity of their ligands and how these relate to the biochemical processes under their control.

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The Pseudomonas aeruginosa PsrA responds to long-chain fatty acid signals to regulate the fadBA5 β-oxidation operon

Cited by 89 publications

References 39 publications

Comparative Genomics of Regulation of Fatty Acid and Branched-Chain Amino Acid Utilization in Proteobacteria

Comparative Genomics of Regulation of Fatty Acid and Branched-Chain Amino Acid Utilization in Proteobacteria

Anr and Its Activation by PlcH Activity in Pseudomonas aeruginosa Host Colonization and Virulence

The TetR Family of Regulators

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