Faculty Opinions recommendation of Regulation of virulence gene expression in Vibrio cholerae by quorum sensing: HapR functions at the aphA promoter.

2002 ◽  
Author(s):  
Bonnie Bassler
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Vibrio Cholerae ◽  
Virulence Gene ◽  
Virulence Gene Expression

scholarly journals Crystal Structure of the Vibrio cholerae Quorum-Sensing Regulatory Protein HapR

2007 ◽  
Vol 189 (15) ◽  
pp. 5683-5691 ◽  
Author(s):  
Rukman S. De Silva ◽  
Gabriela Kovacikova ◽  
Wei Lin ◽  
Ronald K. Taylor ◽  
Karen Skorupski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Crystal Structure ◽  
Dna Binding ◽  
Quorum Sensing ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Regulatory Protein ◽  
Virulence Gene ◽  
Binding Motif ◽  
Virulence Gene Expression

ABSTRACT Quorum sensing in Vibrio cholerae involves signaling between two-component sensor protein kinases and the response regulator LuxO to control the expression of the master regulator HapR. HapR, in turn, plays a central role in regulating a number of important processes, such as virulence gene expression and biofilm formation. We have determined the crystal structure of HapR to 2.2-Å resolution. Its structure reveals a dimeric, two-domain molecule with an all-helical structure that is strongly conserved with members of the TetR family of transcriptional regulators. The N-terminal DNA-binding domain contains a helix-turn-helix DNA-binding motif and alteration of certain residues in this domain completely abolishes the ability of HapR to bind to DNA, alleviating repression of both virulence gene expression and biofilm formation. The C-terminal dimerization domain contains a unique solvent accessible tunnel connected to an amphipathic cavity, which by analogy with other TetR regulators, may serve as a binding pocket for an as-yet-unidentified ligand.

scholarly journals Quorum-sensing regulators control virulence gene expression in Vibrio cholerae

2002 ◽  
Vol 99 (5) ◽  
pp. 3129-3134 ◽  
Author(s):  
J. Zhu ◽  
M. B. Miller ◽  
R. E. Vance ◽  
M. Dziejman ◽  
B. L. Bassler ◽  
...  
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Vibrio Cholerae ◽  
Virulence Gene ◽  
Virulence Gene Expression

scholarly journals Integration Host Factor Positively Regulates Virulence Gene Expression in Vibrio cholerae

2008 ◽  
Vol 190 (13) ◽  
pp. 4736-4748 ◽  
Author(s):  
Emily Stonehouse ◽  
Gabriela Kovacikova ◽  
Ronald K. Taylor ◽  
Karen Skorupski
Keyword(s):  
Gene Expression ◽  
Vibrio Cholerae ◽  
Virulence Gene ◽  
Toxin Production ◽  
Dnase I ◽  
Integration Host Factor ◽  
Host Factor ◽  
Mobility Shift ◽  
Virulence Gene Expression ◽  
Dnase I Footprinting

ABSTRACT Virulence gene expression in Vibrio cholerae is dependent upon a complex transcriptional cascade that is influenced by both specific and global regulators in response to environmental stimuli. Here, we report that the global regulator integration host factor (IHF) positively affects virulence gene expression in V. cholerae. Inactivation of ihfA and ihfB, the genes encoding the IHF subunits, decreased the expression levels of the two main virulence factors tcpA and ctx and prevented toxin-coregulated pilus and cholera toxin production. IHF was found to directly bind to and bend the tcpA promoter region at an IHF consensus site centered at position −162 by using gel mobility shift assays and DNase I footprinting experiments. Deletion or mutation of the tcpA IHF consensus site resulted in the loss of IHF binding and additionally disrupted the binding of the repressor H-NS. DNase I footprinting revealed that H-NS protection overlaps with both the IHF and the ToxT binding sites at the tcpA promoter. In addition, disruption of ihfA in an hns or toxT mutant background had no effect on tcpA expression. These results suggest that IHF may function at the tcpA promoter to alleviate H-NS repression.

scholarly journals TolC Affects Virulence Gene Expression in Vibrio cholerae

2011 ◽  
Vol 193 (20) ◽  
pp. 5850-5852 ◽  
Author(s):  
Y. Minato ◽  
R. L. Siefken ◽  
C. C. Hase
Keyword(s):  
Gene Expression ◽  
Vibrio Cholerae ◽  
Virulence Gene ◽  
Virulence Gene Expression

scholarly journals Integration of Cyclic di-GMP and Quorum Sensing in the Control ofvpsTandaphAin Vibrio cholerae

2011 ◽  
Vol 193 (22) ◽  
pp. 6331-6341 ◽  
Author(s):  
Disha Srivastava ◽  
Rebecca C. Harris ◽  
Christopher M. Waters
Keyword(s):  
Quorum Sensing ◽  
Binding Site ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Transcriptional Activator ◽  
Transcriptional Regulators ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Signaling Systems

Vibrio choleraetransitions between aquatic environmental reservoirs and infection in the gastrointestinal tracts of human hosts. The second-messenger molecule cyclic di-GMP (c-di-GMP) and quorum sensing (QS) are important signaling systems that enableV. choleraeto alternate between these distinct environments by controlling biofilm formation and virulence factor expression. Here we identify a conserved regulatory mechanism inV. choleraethat integrates c-di-GMP and QS to control the expression of two transcriptional regulators:aphA, an activator of virulence gene expression and an important regulator of the quorum-sensing pathway, andvpsT, a transcriptional activator that induces biofilm formation. Surprisingly,aphAexpression was induced by c-di-GMP. Activation of bothaphAandvpsTby c-di-GMP requires the transcriptional activator VpsR, which binds to c-di-GMP. The VpsR binding site at each of these promoters overlaps with the binding site of HapR, the master QS regulator at high cell densities. Our results suggest thatV. choleraecombines information conveyed by QS and c-di-GMP to appropriately respond and adapt to divergent environments by modulating the expression of key transcriptional regulators.

scholarly journals Regulatory Networks Controlling Vibrio cholerae Virulence Gene Expression

2007 ◽  
Vol 75 (12) ◽  
pp. 5542-5549 ◽  
Author(s):  
Jyl S. Matson ◽  
Jeffrey H. Withey ◽  
Victor J. DiRita
Keyword(s):  
Gene Expression ◽  
Vibrio Cholerae ◽  
Regulatory Networks ◽  
Virulence Gene ◽  
Virulence Gene Expression
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