Phosphotyrosine-Mediated Regulation of Enterohemorrhagic Escherichia coli Virulence

ABSTRACTEnteric pathogens with low infectious doses rely on the ability to orchestrate the expression of virulence and metabolism-associated genes in response to environmental cues for successful infection. Accordingly, the human pathogen enterohemorrhagicEscherichia coli(EHEC) employs a complex multifaceted regulatory network to link the expression of type III secretion system (T3SS) components to nutrient availability. While phosphorylation of histidine and aspartate residues on two-component system response regulators is recognized as an integral part of bacterial signaling, the involvement of phosphotyrosine-mediated control is minimally explored in Gram-negative pathogens. Our recent phosphotyrosine profiling study ofE. coliidentified 342 phosphorylated proteins, indicating that phosphotyrosine modifications in bacteria are more prevalent than previously anticipated. The present study demonstrates that tyrosine phosphorylation of a metabolite-responsive LacI/GalR family regulator, Cra, negatively affects T3SS expression under glycolytic conditions that are typical for the colonic lumen environment where production of the T3SS is unnecessary. Our data suggest that Cra phosphorylation affects T3SS expression by modulating the expression ofler, which encodes the major activator of EHEC virulence gene expression. Phosphorylation of the Cra Y47 residue diminishes DNA binding to fine-tune the expression of virulence-associated genes, including those of the locus of enterocyte effacement pathogenicity island that encode the T3SS, and thereby negatively affects the formation of attaching and effacing lesions. Our data indicate that tyrosine phosphorylation provides an additional mechanism to control the DNA binding of Cra and other LacI/GalR family regulators, including LacI and PurR. This study describes an initial effort to unravel the role of global phosphotyrosine signaling in the control of EHEC virulence potential.IMPORTANCEEnterohemorrhagicEscherichia coli(EHEC) causes outbreaks of hemorrhagic colitis and the potentially fatal hemolytic-uremic syndrome. Successful host colonization by EHEC relies on the ability to coordinate the expression of virulence factors in response to environmental cues. A complex network that integrates environmental signals at multiple regulatory levels tightly controls virulence gene expression. We demonstrate that EHEC utilizes a previously uncharacterized phosphotyrosine signaling pathway through Cra to fine-tune the expression of virulence-associated genes to effectively control T3SS production. This study demonstrates that tyrosine phosphorylation negatively affects the DNA-binding capacity of Cra, which affects the expression of genes related to virulence and metabolism. We demonstrate for the first time that phosphotyrosine-mediated control affects global transcription in EHEC. Our data provide insight into a hitherto unexplored regulatory level of the global network controlling EHEC virulence gene expression.

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Bacteriophage Transcription Factor Cro Regulates Virulence Gene Expression in Enterohemorrhagic Escherichia coli

Cell Host & Microbe ◽

10.1016/j.chom.2018.04.007 ◽

2018 ◽

Vol 23 (5) ◽

pp. 607-617.e6 ◽

Cited By ~ 18

Author(s):

Juan D. Hernandez-Doria ◽

Vanessa Sperandio

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Transcription Factor ◽

Virulence Gene ◽

Enterohemorrhagic Escherichia Coli ◽

Virulence Gene Expression

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Coordinate regulation of virulence gene expression in enterohemorrhagic Escherichia coli

Nippon Saikingaku Zasshi ◽

10.3412/jsb.63.407 ◽

2008 ◽

Vol 63 (3) ◽

pp. 407-415

Author(s):

Sunao IYODA

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Virulence Gene ◽

Enterohemorrhagic Escherichia Coli ◽

Coordinate Regulation ◽

Virulence Gene Expression

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Transcriptional Activator OvrA Encoded in O Island 19 Modulates Virulence Gene Expression in Enterohemorrhagic Escherichia coli O157:H7

The Journal of Infectious Diseases ◽

10.1093/infdis/jiz458 ◽

2019 ◽

Author(s):

Bin Liu ◽

Junyue Wang ◽

Lu Wang ◽

Peng Ding ◽

Pan Yang ◽

...

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Gene Promoter ◽

Virulence Gene ◽

Coli Strain ◽

Enterohemorrhagic Escherichia Coli ◽

Bacterial Adherence ◽

Host Cells ◽

Virulence Gene Expression ◽

E Coli

AbstractThe human intestinal pathogen enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes bloody diarrhea, hemorrhagic colitis, and fatal hemolytic uremic syndrome. Its genome contains 177 unique O islands (OIs), which contribute largely to the high virulence and pathogenicity although most OI genes remain uncharacterized. In the current study, we demonstrated that OI-19 is required for EHEC O157:H7 adherence to host cells. Z0442 (OI-encoded virulence regulator A [OvrA]) encoded in OI-19 positively regulated bacterial adherence by activating locus of enterocyte effacement (LEE) gene expression through direct OvrA binding to the gene promoter region of the LEE gene master regulator Ler. Mouse colonization experiments revealed that OvrA promotes EHEC O157:H7 adherence in mouse intestine, preferentially the colon. Finally, OvrA also regulated virulence in other non-O157 pathogenic E. coli, including EHEC strains O145:H28 and O157:H16 and enteropathogenic E. coli strain O55:H7. Our work markedly enriches the understanding of bacterial adherence control and provides another example of laterally acquired regulators that mediate LEE gene expression.

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The Norepinephrine Metabolite 3,4-Dihydroxymandelic Acid Is Produced by the Commensal Microbiota and Promotes Chemotaxis and Virulence Gene Expression in Enterohemorrhagic Escherichia coli

Infection and Immunity ◽

10.1128/iai.00431-17 ◽

2017 ◽

Vol 85 (10) ◽

Cited By ~ 10

Author(s):

Nitesh Sule ◽

Sasi Pasupuleti ◽

Nandita Kohli ◽

Rani Menon ◽

Lawrence J. Dangott ◽

...

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Virulence Gene ◽

The United States ◽

Enterohemorrhagic Escherichia Coli ◽

Dependent Manner ◽

Content Type ◽

Virulence Gene Expression ◽

E Coli ◽

Commensal Microbiota

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) is a commonly occurring foodborne pathogen responsible for numerous multistate outbreaks in the United States. It is known to infect the host gastrointestinal tract, specifically, in locations associated with lymphoid tissue. These niches serve as sources of enteric neurotransmitters, such as epinephrine and norepinephrine, that are known to increase virulence in several pathogens, including enterohemorrhagic E. coli. The mechanisms that allow pathogens to target these niches are poorly understood. We previously reported that 3,4-dihydroxymandelic acid (DHMA), a metabolite of norepinephrine produced by E. coli, is a chemoattractant for the nonpathogenic E. coli RP437 strain. Here we report that DHMA is also a chemoattractant for EHEC. In addition, DHMA induces the expression of EHEC virulence genes and increases attachment to intestinal epithelial cells in vitro in a QseC-dependent manner. We also show that DHMA is present in murine gut fecal contents and that its production requires the presence of the commensal microbiota. On the basis of its ability to both attract and induce virulence gene expression in EHEC, we propose that DHMA acts as a molecular beacon to target pathogens to their preferred sites of infection in vivo.

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Pathovar Transcriptomes

mSystems ◽

10.1128/msystems.00049-17 ◽

2017 ◽

Vol 2 (4) ◽

Cited By ~ 1

Author(s):

Amy Platenkamp ◽

Jay L. Mellies

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Regulatory Networks ◽

Virulence Gene ◽

Model System ◽

Genomic Sequences ◽

Bacterial Strains ◽

Content Type ◽

Virulence Gene Expression ◽

Link Type

ABSTRACT Archetypal pathogenic bacterial strains are often used to elucidate regulatory networks of an entire pathovar, which encompasses multiple lineages and phylogroups. With enteropathogenic Escherichia coli (EPEC) as a model system, Hazen and colleagues (mSystems 6:e00024-17, 2017, https://doi.org/10.1128/mSystems.00024-17 ) used 9 isolates representing 8 lineages and 3 phylogroups to find that isolates with similar genomic sequences exhibit similarities in global transcriptomes under conditions of growth in medium that induces virulence gene expression, and they found variation among individual isolates. Archetypal pathogenic bacterial strains are often used to elucidate regulatory networks of an entire pathovar, which encompasses multiple lineages and phylogroups. With enteropathogenic Escherichia coli (EPEC) as a model system, Hazen and colleagues (mSystems 6:e00024-17, 2017, https://doi.org/10.1128/mSystems.00024-17 ) used 9 isolates representing 8 lineages and 3 phylogroups to find that isolates with similar genomic sequences exhibit similarities in global transcriptomes under conditions of growth in medium that induces virulence gene expression. They also found variation among individual isolates. Their work illustrates the importance of moving beyond observing regulatory phenomena of a limited number of regulons in a few archetypal strains, with the possibility of correlating clinical symptoms to key transcriptional pathways across lineages and phylogroups.

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H-NS regulation of virulence gene expression in enteroinvasive Escherichia coli harboring the virulence plasmid integrated into the host chromosome.

Journal of Bacteriology ◽

10.1128/jb.177.16.4703-4712.1995 ◽

1995 ◽

Vol 177 (16) ◽

pp. 4703-4712 ◽

Cited By ~ 51

Author(s):

B Colonna ◽

M Casalino ◽

P A Fradiani ◽

C Zagaglia ◽

S Naitza ◽

...

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Virulence Gene ◽

Virulence Plasmid ◽

Host Chromosome ◽

Virulence Gene Expression

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Reconstitution of Acetosyringone-Mediated Agrobacterium tumefaciens Virulence Gene Expression in the Heterologous Host Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.183.12.3704-3711.2001 ◽

2001 ◽

Vol 183 (12) ◽

pp. 3704-3711 ◽

Cited By ~ 23

Author(s):

Scott M. Lohrke ◽

Hongjiang Yang ◽

Shouguang Jin

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Agrobacterium Tumefaciens ◽

Virulence Genes ◽

Virulence Gene ◽

Dependent Manner ◽

Gene Encoding ◽

Virulence Gene Expression ◽

E Coli ◽

Glucose Binding

ABSTRACT The ability to utilize Escherichia coli as a heterologous system in which to study the regulation ofAgrobacterium tumefaciens virulence genes and the mechanism of transfer DNA (T-DNA) transfer would provide an important tool to our understanding and manipulation of these processes. We have previously reported that the rpoA gene encoding the alpha subunit of RNA polymerase is required for the expression of lacZ gene under the control of virB promoter (virBp::lacZ) in E. colicontaining a constitutively active virG gene [virG(Con)]. Here we show that an RpoA hybrid containing the N-terminal 247 residues from E. coli and the C-terminal 89 residues from A. tumefaciens was able to significantly express virBp::lacZ in E. coli in a VirG(Con)-dependent manner. Utilization oflac promoter-driven virA and virGin combination with the A. tumefaciens rpoA construct resulted in significant inducer-mediated expression of thevirBp::lacZ fusion, and the level ofvirBp::lacZ expression was positively correlated to the copy number of the rpoA construct. This expression was dependent on VirA, VirG, temperature, and, to a lesser extent, pH, which is similar to what is observed in A. tumefaciens. Furthermore, the effect of sugars on virgene expression was observed only in the presence of thechvE gene, suggesting that the glucose-binding protein ofE. coli, a homologue of ChvE, does not interact with the VirA molecule. We also evaluated other phenolic compounds in induction assays and observed significant expression with syringealdehyde, a low level of expression with acetovanillone, and no expression with hydroxyacetophenone, similar to what occurs in A. tumefaciens strain A348 from which the virA clone was derived. These data support the notion that VirA directly senses the phenolic inducer. However, the overall level of expression of thevir genes in E. coli is less than what is observed in A. tumefaciens, suggesting that additional gene(s) from A. tumefaciens may be required for the full expression of virulence genes in E. coli.

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