AphA and LuxR/HapR reciprocally control quorum sensing in vibrios.

TitleAphA and LuxR/HapR reciprocally control quorum sensing in vibrios.
Publication TypeJournal Article
Year of Publication2011
AuthorsRutherford, ST, van Kessel, JC, Shao, Y, Bassler, BL
JournalGenes Dev
Date Published2011 Feb 15
KeywordsBacterial Proteins, Base Sequence, Gene Expression Profiling, Gene Expression Regulation, Bacterial, Microarray Analysis, Models, Biological, Molecular Sequence Data, Quorum Sensing, Repressor Proteins, Sequence Homology, Nucleic Acid, Trans-Activators, Vibrio

<p>Bacteria cycle between periods when they perform individual behaviors and periods when they perform group behaviors. These transitions are controlled by a cell-cell communication process called quorum sensing, in which extracellular signal molecules, called autoinducers (AIs), are released, accumulate, and are synchronously detected by a group of bacteria. AI detection results in community-wide changes in gene expression, enabling bacteria to collectively execute behaviors such as bioluminescence, biofilm formation, and virulence factor production. In this study, we show that the transcription factor AphA is a master regulator of quorum sensing that operates at low cell density (LCD) in Vibrio harveyi and Vibrio cholerae. In contrast, LuxR (V. harveyi)/HapR (V. cholerae) is the master regulator that operates at high cell density (HCD). At LCD, redundant small noncoding RNAs (sRNAs) activate production of AphA, and AphA and the sRNAs repress production of LuxR/HapR. Conversely, at HCD, LuxR/HapR represses aphA. This network architecture ensures maximal AphA production at LCD and maximal LuxR/HapR production at HCD. Microarray analyses reveal that 300 genes are regulated by AphA at LCD in V. harveyi, a subset of which is also controlled by LuxR. We propose that reciprocal gradients of AphA and LuxR/HapR establish the quorum-sensing LCD and HCD gene expression patterns, respectively.</p>

Alternate JournalGenes Dev.
PubMed ID21325136
PubMed Central IDPMC3042162
Grant List5R01AI054442 / AI / NIAID NIH HHS / United States
5R01GM065859 / GM / NIGMS NIH HHS / United States
F32AI085922 / AI / NIAID NIH HHS / United States
F32GM089019 / GM / NIGMS NIH HHS / United States
P50 GM071508 / GM / NIGMS NIH HHS / United States
/ / Howard Hughes Medical Institute / United States