Regulation of quorum sensing in Vibrio harveyi by LuxO and sigma-54.

TitleRegulation of quorum sensing in Vibrio harveyi by LuxO and sigma-54.
Publication TypeJournal Article
Year of Publication2000
AuthorsLilley, BN, Bassler, BL
JournalMol Microbiol
Date Published2000 May
KeywordsAmino Acid Sequence, Bacterial Proteins, Binding Sites, Cloning, Molecular, DNA-Binding Proteins, DNA-Directed RNA Polymerases, Enzyme Activation, Molecular Sequence Data, Mutagenesis, Phenotype, Repressor Proteins, RNA Polymerase Sigma 54, Sigma Factor, Transcription Factors, Vibrio

<p>The bioluminescent marine bacterium Vibrio harveyi controls light production (lux) by an elaborate quorum-sensing circuit. V. harveyi produces and responds to two different autoinducer signals (AI-1 and AI-2) to modulate the luciferase structural operon (luxCDABEGH) in response to changes in cell-population density. Unlike all other Gram-negative quorum-sensing organisms, V. harveyi regulates quorum sensing using a two-component phosphorylation-dephosphorylation cascade. Each autoinducer is recognized by a cognate hybrid sensor kinase (called LuxN and LuxQ). Both sensors transduce information to a shared phosphorelay protein called LuxU, which in turn conveys the signal to the response regulator protein LuxO. Phospho-LuxO is responsible for repression of luxCDABEGH expression at low cell density. In the present study, we demonstrate that LuxO functions as an activator protein via interaction with the alternative sigma factor, sigma54 (encoded by rpoN). Our results suggest that LuxO, together with sigma54, activates the expression of a negative regulator of luminescence. We also show that phenotypes other than lux are regulated by LuxO and sigma54, demonstrating that in Vibrio harveyi, quorum sensing controls multiple processes.</p>

Alternate JournalMol Microbiol
PubMed ID10844680