A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis

  1. Nick D Pokorzynski
  2. Amanda J Brinkworth
  3. Rey Carabeo  Is a corresponding author
  1. Washington State University, United States

Abstract

During infection, pathogens are starved of essential nutrients such as iron and tryptophan by host immune effectors. Without conserved global stress response regulators, how the obligate intracellular bacterium Chlamydia trachomatis arrives at a physiologically similar 'persistent' state in response to starvation of either nutrient remains unclear. Here, we report on the iron-dependent regulation of the trpRBA tryptophan salvage pathway in C. trachomatis. Iron starvation specifically induces trpBA expression from a novel promoter element within an intergenic region flanked by trpR and trpB. YtgR, the only known iron-dependent regulator in Chlamydia, can bind to the trpRBA intergenic region upstream of the alternative trpBA promoter to repress transcription. Simultaneously, YtgR binding promotes the termination of transcripts from the primary promoter upstream of trpR. This is the first description of an iron-dependent mechanism regulating prokaryotic tryptophan biosynthesis that may indicate the existence of novel approaches to gene regulation and stress response in Chlamydia.

Data availability

Raw and processed sequencing data have been deposited in the Gene Expression Omnibus (Accesssion number GSE106763).

The following previously published data sets were used

Article and author information

Author details

  1. Nick D Pokorzynski

    Center for Reproductive Biology, Washington State University, Pullman, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2438-2368
  2. Amanda J Brinkworth

    Center for Reproductive Biology, Washington State University, Pullman, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Rey Carabeo

    Center for Reproductive Biology, Washington State University, Pullman, United States
    For correspondence
    rey.carabeo@wsu.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5708-5493

Funding

National Institutes of Health (AI065545)

  • Rey Carabeo

Achievement Rewards for College Scientists Foundation

  • Nick D Pokorzynski

National Institutes of Health (F31AI136295)

  • Nick D Pokorzynski

National Institutes of Health (T32GM008336)

  • Nick D Pokorzynski

National Institutes of Health (T32AI007025)

  • Amanda J Brinkworth

National Institutes of Health (AI132406)

  • Rey Carabeo

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Gisela Storz, National Institute of Child Health and Human Development, United States

Publication history

  1. Received: September 24, 2018
  2. Accepted: March 30, 2019
  3. Accepted Manuscript published: April 2, 2019 (version 1)
  4. Version of Record published: May 7, 2019 (version 2)

Copyright

© 2019, Pokorzynski et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Nick D Pokorzynski
  2. Amanda J Brinkworth
  3. Rey Carabeo
(2019)
A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
eLife 8:e42295.
https://doi.org/10.7554/eLife.42295

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