The phosphorylation flow of the Vibrio harveyi quorum-sensing cascade determines levels of phenotypic heterogeneity in the population
Abstract
Quorum sensing (QS) is a communication process that enables a bacterial population to coordinate and synchronize specific behaviors. The bioluminescent marine bacterium Vibrio harveyi integrates three autoinducer (AI) signals into one quorum-sensing cascade comprising a phosphorelay involving three hybrid sensor kinases: LuxU; LuxO, an Hfq/small RNA (sRNA) switch; and the transcriptional regulator LuxR. Using a new set of V. harveyi mutants lacking genes for the AI synthases and/or sensors, we assayed the activity of the quorum-sensing cascade at the population and single-cell levels, with a specific focus on signal integration and noise levels. We found that the ratios of kinase activities to phosphatase activities of the three sensors and, hence, the extent of phosphorylation of LuxU/LuxO are important not only for the signaling output but also for the degree of noise in the system. The pools of phosphorylated LuxU/LuxO per cell directly determine the amounts of sRNAs produced and, consequently, the copy number of LuxR, generating heterogeneous quorum-sensing activation at the single-cell level. We conclude that the ability to drive the heterogeneous expression of QS-regulated genes in V. harveyi is an inherent feature of the...Continue Reading
References
Bioinformatics and experimental analysis of proteins of two-component systems in Myxococcus xanthus.
A modular view of the diversity of cell-density-encoding schemes in bacterial quorum-sensing systems
A qrr noncoding RNA deploys four different regulatory mechanisms to optimize quorum-sensing dynamics
Citations
Related Concepts
Related Feeds
Biofilm & Infectious Disease
Biofilm formation is a key virulence factor for a wide range of microorganisms that cause chronic infections.Here is the latest research on biofilm and infectious diseases.
Biofilms
Biofilms are adherent bacterial communities embedded in a polymer matrix and can cause persistent human infections that are highly resistant to antibiotics. Discover the latest research on Biofilms here.