Premium
Integration host factor and LuxR synergistically bind DNA to coactivate quorum‐sensing genes in Vibrio harveyi
Author(s) -
Chaparian Ryan R.,
Olney Stephen G.,
Hustmyer Christine M.,
RoweMagnus Dean A.,
van Kessel Julia C.
Publication year - 2016
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13425
Subject(s) - vibrio harveyi , biology , quorum sensing , bioreporter , transcription factor , promoter , gene , genetics , autoinducer , operon , dna binding site , bioluminescence , reporter gene , vibrio , microbiology and biotechnology , gene expression , escherichia coli , virulence , bacteria , ecology
Summary The cell–cell signaling process called quorum sensing allows bacteria to control behaviors in response to changes in population density. In Vibrio harveyi , the master quorum‐sensing transcription factor LuxR is a member of the TetR family of transcription factors that both activates and represses genes to coordinate group behaviors, including bioluminescence. Here, we show that integration host factor (IHF) is a key coactivator of the luxCDABE bioluminescence genes that is required together with LuxR for precise timing and expression levels of bioluminescence during quorum sensing. IHF binds to multiple sites in the luxCDABE promoter and bends the DNA in vitro . IHF and LuxR synergistically bind luxCDABE promoter DNA at overlapping, essential binding sites that are required for maximal gene expression in vivo . RNA‐seq analysis demonstrated that IHF regulates 300 genes in V. harveyi , and among these are a core set of 19 genes that are also directly bound and regulated by LuxR. We validated these global analyses by demonstrating that both IHF and LuxR are required for transcriptional activation of the osmotic stress response genes betIBA‐proXWV . These data suggest that IHF plays an integral role in one mechanism of transcriptional activation by the LuxR‐type family of quorum‐sensing regulators in vibrios.