1. Microbiology and Infectious Disease

HetL, HetR and PatS form a reaction-diffusion system to control pattern formation in the cyanobacterium Nostoc PCC 7120

  1. Xiaomei Xu
  2. Véronique Risoul
  3. Deborah Byrne
  4. Stéphanie Champ
  5. Badreddine Douzi
  6. Amel Latifi  Is a corresponding author
  1. Aix-Marseille University-CNRS, France
  2. Aix-Marseille university-CNRS, France
  3. Institut de Microbiologie de la Méditerranée, CNRS, France
  4. Aix-Marseille university, CNRS, France
  5. Universite de Lorraine, Inra, France
https://doi.org/10.7554/eLife.59190
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  1. Xiaomei Xu
  2. Véronique Risoul
  3. Deborah Byrne
  4. Stéphanie Champ
  5. Badreddine Douzi
  6. Amel Latifi
(2020)
HetL, HetR and PatS form a reaction-diffusion system to control pattern formation in the cyanobacterium Nostoc PCC 7120
eLife 9:e59190.
https://doi.org/10.7554/eLife.59190
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Abstract

Local activation and long-range inhibition are mechanisms conserved in self-organizing systems leading to biological patterns. A number of them involve the production by the developing cell of an inhibitory morphogen, but how this cell becomes immune to self-inhibition is rather unknown. Under combined nitrogen starvation, the multicellular cyanobacterium Nostoc PCC 7120 develops nitrogen-fixing heterocysts with a pattern of one heterocyst every 10-12 vegetative cells. Cell differentiation is regulated by HetR which activates the synthesis of its own inhibitory morphogens, diffusion of which establishes the differentiation pattern. Here we show that HetR interacts with HetL at the same interface as PatS, and that this interaction is necessary to suppress inhibition and to differentiate heterocysts. hetL expression is induced under nitrogen-starvation and is activated by HetR, suggesting that HetL provides immunity to the heterocyst. This protective mechanism might be conserved in other differentiating cyanobacteria as HetL homologues are spread across the phylum.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Source data files are provided for bacterial two hybrid analysis, qRT-PCR and heterocyst intervals and percentages

Article and author information

Author details

  1. Xiaomei Xu

    Laboatoire de chimie bactérienne, Aix-Marseille University-CNRS, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.

  2. Véronique Risoul

    Laboratoire de chimie bactérienne, Aix-Marseille university-CNRS, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.

  3. Deborah Byrne

    Protein Purification Platform, Institut de Microbiologie de la Méditerranée, CNRS, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.

  4. Stéphanie Champ

    Laboratoire de chimie bactérienne, Aix-Marseille university, CNRS, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.

  5. Badreddine Douzi

    INRAE DynAMic, Universite de Lorraine, Inra, Nancy, France
    Competing interests
    The authors declare that no competing interests exist.

  6. Amel Latifi

    Laboratoire de Chimie Bactérienne, Aix-Marseille university-CNRS, Marseille, France
    For correspondence
    latifi@imm.cnrs.fr
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0776-7349

Funding

Centre National de la Recherche Scientifique

  • Xiaomei Xu

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

Reviewing Editor

  1. Susan Golden

Version history

  1. Received: May 22, 2020
  2. Accepted: August 6, 2020
  3. Accepted Manuscript published: August 7, 2020 (version 1)
  4. Version of Record published: September 7, 2020 (version 2)

Copyright

© 2020, Xu 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. Xiaomei Xu
  2. Véronique Risoul
  3. Deborah Byrne
  4. Stéphanie Champ
  5. Badreddine Douzi
  6. Amel Latifi
(2020)
HetL, HetR and PatS form a reaction-diffusion system to control pattern formation in the cyanobacterium Nostoc PCC 7120
eLife 9:e59190.
https://doi.org/10.7554/eLife.59190

Share this article

https://doi.org/10.7554/eLife.59190

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