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Distinct intraspecies virulence mechanisms regulated by a conserved transcription factor

Lookup NU author(s): Dr James ConnollyORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© 2019 National Academy of Sciences. All rights reserved.Tailoring transcriptional regulation to coordinate the expression of virulence factors in tandem with the core genome is a hallmark of bacterial pathogen evolution. Bacteria encode hundreds of transcription factors forming the base-level control of gene regulation. Moreover, highly homologous regulators are assumed to control conserved genes between members within a species that harbor the same genetic targets. We have explored this concept in 2 Escherichia coli pathotypes that employ distinct virulence mechanisms that facilitate specification of a different niche within the host. Strikingly, we found that the transcription factor YhaJ actively regulated unique gene sets between intestinal enterohemorrhagic E. coli (EHEC) and extraintestinal uropathogenic E. coli (UPEC), despite being very highly conserved. In EHEC, YhaJ directly activates expression of type 3 secretion system components and effectors. Alternatively, YhaJ enhances UPEC virulence regulation by binding directly to the phase-variable type 1 fimbria promoter, driving its expression. Additionally, YhaJ was found to override the universal GAD acid tolerance system but exclusively in EHEC, thereby indirectly enhancing type 3 secretion pleiotropically. These results have revealed that within a species, conserved regulators are actively repurposed in a "personalized" manner to benefit particular lifestyles and drive virulence via multiple distinct mechanisms.

Publication metadata

Author(s): Connolly JPR, O'Boyle N, Turner NCA, Browning DF, Roe AJ

Publication type: Article

Publication status: Published

Journal: Proceedings of the National Academy of Sciences of the United States of America

Year: 2019

Volume: 116

Issue: 39

Pages: 19695-19704

Print publication date: 24/09/2019

Online publication date: 09/09/2019

Acceptance date: 15/08/2019

Date deposited: 01/10/2019

ISSN (print): 0027-8424

ISSN (electronic): 1091-6490

Publisher: National Academy of Sciences


DOI: 10.1073/pnas.1903461116

PubMed id: 31501343


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