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The hierarchy quorum sensing network in Pseudomonas aeruginosa.

Lee J, Zhang L - Protein Cell (2014)

Bottom Line: The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms.Evidence is accumulating that the QS regulatory network not only responds to bacterial population changes but also could react to environmental stress cues.This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore.

ABSTRACT
Pseudomonas aeruginosa causes severe and persistent infections in immune compromised individuals and cystic fibrosis sufferers. The infection is hard to eradicate as P. aeruginosa has developed strong resistance to most conventional antibiotics. The problem is further compounded by the ability of the pathogen to form biofilm matrix, which provides bacterial cells a protected environment withstanding various stresses including antibiotics. Quorum sensing (QS), a cell density-based intercellular communication system, which plays a key role in regulation of the bacterial virulence and biofilm formation, could be a promising target for developing new strategies against P. aeruginosa infection. The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms. Evidence is accumulating that the QS regulatory network not only responds to bacterial population changes but also could react to environmental stress cues. This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.

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Related in: MedlinePlus

Schematic representation of the four QS signaling networks inP. aeruginosaand their respective regulons. Arrows indicate a stimulatory effect. Perpendicular lines indicate an inhibitory effect
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Fig3: Schematic representation of the four QS signaling networks inP. aeruginosaand their respective regulons. Arrows indicate a stimulatory effect. Perpendicular lines indicate an inhibitory effect

Mentions: With las governing the expression of both pqs and rhl systems, it was often described as being at the top of the QS hierarchy. The rhl system on the other hand, is under the control of both las and pqs, yet many QS-dependent virulence factors are predominantly activated by RhlR-BHL (Latifi et al., 1995; Schuster and Greenberg, 2007; Schuster et al., 2004; Whiteley et al., 1999; Winzer et al., 2000), thus the rhl system functions like a workhorse for the QS command. Since LasR-OdDHL controls the onset and activation of both the pqs and rhl QS circuits, these systems therefore represent a step-wise activation cascade that will be triggered by attainment of a “quorum” in P. aeruginosa cultures. The recently identified IQS was also found to be tightly controlled by LasRI under rich medium conditions. Disruption of either lasR or lasI completely abrogates the expression of ambBCDE and the production of IQS (Lee et al., 2013) (Fig. 3).Figure 3


The hierarchy quorum sensing network in Pseudomonas aeruginosa.

Lee J, Zhang L - Protein Cell (2014)

Schematic representation of the four QS signaling networks inP. aeruginosaand their respective regulons. Arrows indicate a stimulatory effect. Perpendicular lines indicate an inhibitory effect
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4286720&req=5

Fig3: Schematic representation of the four QS signaling networks inP. aeruginosaand their respective regulons. Arrows indicate a stimulatory effect. Perpendicular lines indicate an inhibitory effect
Mentions: With las governing the expression of both pqs and rhl systems, it was often described as being at the top of the QS hierarchy. The rhl system on the other hand, is under the control of both las and pqs, yet many QS-dependent virulence factors are predominantly activated by RhlR-BHL (Latifi et al., 1995; Schuster and Greenberg, 2007; Schuster et al., 2004; Whiteley et al., 1999; Winzer et al., 2000), thus the rhl system functions like a workhorse for the QS command. Since LasR-OdDHL controls the onset and activation of both the pqs and rhl QS circuits, these systems therefore represent a step-wise activation cascade that will be triggered by attainment of a “quorum” in P. aeruginosa cultures. The recently identified IQS was also found to be tightly controlled by LasRI under rich medium conditions. Disruption of either lasR or lasI completely abrogates the expression of ambBCDE and the production of IQS (Lee et al., 2013) (Fig. 3).Figure 3

Bottom Line: The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms.Evidence is accumulating that the QS regulatory network not only responds to bacterial population changes but also could react to environmental stress cues.This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore.

ABSTRACT
Pseudomonas aeruginosa causes severe and persistent infections in immune compromised individuals and cystic fibrosis sufferers. The infection is hard to eradicate as P. aeruginosa has developed strong resistance to most conventional antibiotics. The problem is further compounded by the ability of the pathogen to form biofilm matrix, which provides bacterial cells a protected environment withstanding various stresses including antibiotics. Quorum sensing (QS), a cell density-based intercellular communication system, which plays a key role in regulation of the bacterial virulence and biofilm formation, could be a promising target for developing new strategies against P. aeruginosa infection. The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms. Evidence is accumulating that the QS regulatory network not only responds to bacterial population changes but also could react to environmental stress cues. This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.

Show MeSH
Related in: MedlinePlus