Abstract
Bacteria have evolved elaborate communication strategies to co-ordinate their group activities, a process termed quorum sensing (QS). Pseudomonas aeruginosa is an opportunistic pathogen that utilizes QS for diverse activities, including disease pathogenesis. P. aeruginosa has evolved a novel communication system in which the signal molecule 2-heptyl-3-hydroxy-4-quinolone (Pseudomonas Quinolone Signal, PQS) is trafficked between cells via membrane vesicles (MVs). Not only is PQS packaged into MVs, it is required for MV formation. Although MVs are involved in important biological processes aside from signalling, the molecular mechanism of MV formation is unknown. To provide insight into the molecular mechanism of MV formation, we examined the interaction of PQS with bacterial lipids. Here, we show that PQS interacts strongly with the acyl chains and 4′-phosphate of bacterial lipopolysaccharide (LPS). Using PQS derivatives, we demonstrate that the alkyl side-chain and third position hydroxyl of PQS are critical for these interactions. Finally, we show that PQS stimulated purified LPS to form liposome-like structures. These studies provide molecular insight into P. aeruginosa MV formation and demonstrate that quorum signals serve important non-signalling functions.
Highlights
Pseudomonas aeruginosa is a ubiquitous Gram-negative bacterium and a frequent cause of opportunistic infections in immunocompromised individuals
Is PQS packaged into membrane vesicles (MVs), it is required for MV formation
MVs are involved in important biological processes aside from signalling, the molecular mechanism of MV formation is unknown
Summary
Bacteria have evolved elaborate communication strategies to co-ordinate their group activities, a process termed quorum sensing (QS). P. aeruginosa has evolved a novel communication system in which the signal molecule 2-heptyl-3-hydroxy-4-quinolone (Pseudomonas Quinolone Signal, PQS) is trafficked between cells via membrane vesicles (MVs). Is PQS packaged into MVs, it is required for MV formation. MVs are involved in important biological processes aside from signalling, the molecular mechanism of MV formation is unknown. To provide insight into the molecular mechanism of MV formation, we examined the interaction of PQS with bacterial lipids. We show that PQS interacts strongly with the acyl chains and 4Ј-phosphate of bacterial lipopolysaccharide. We show that PQS stimulated purified LPS to form liposome-like structures. These studies provide molecular insight into P. aeruginosa MV formation and demonstrate that quorum signals serve important non-signalling functions
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.