Control and regulation of acetate overflow in Escherichia coli

  1. Pierre Millard  Is a corresponding author
  2. Brice Enjalbert
  3. Sandrine Uttenweiler-Joseph
  4. Jean-Charles Portais
  5. Fabien Letisse
  1. TBI, Universite de Toulouse, CNRS, INRAE, INSA, France
  2. Université de Toulouse, France

Abstract

Overflow metabolism refers to the production of seemingly wasteful by-products by cells during growth on glucose even when oxygen is abundant. Two theories have been proposed to explain acetate overflow in Escherichia coli – global control of the central metabolism and local control of the acetate pathway – but neither accounts for all observations. Here, we develop a kinetic model of E. coli metabolism that quantitatively accounts for observed behaviors and successfully predicts the response of E. coli to new perturbations. We reconcile these theories and clarify the origin, control and regulation of the acetate flux. We also find that, in turns, acetate regulates glucose metabolism by coordinating the expression of glycolytic and TCA genes. Acetate should not be considered a wasteful end-product since it is also a co-substrate and a global regulator of glucose metabolism in E. coli. This has broad implications for our understanding of overflow metabolism.

Data availability

Transcriptomics data have been deposited in ArrayExpress under accession code E-MTAB-9086.The calibrated kinetic model has been deposited in BioModels database under accession code MODEL2005050001.All the scripts used to perform the simulations, to analyse the models and to generate the figures are provided in the supporting files and at https://github.com/MetaSys-LISBP/acetate_regulationAll data generated or analysed during this study are included in the manuscript and supporting files.

The following data sets were generated

Article and author information

Author details

  1. Pierre Millard

    Systems biology, TBI, Universite de Toulouse, CNRS, INRAE, INSA, Toulouse, France
    For correspondence
    millard@insa-toulouse.fr
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8136-9963
  2. Brice Enjalbert

    Systems biology, TBI, Universite de Toulouse, CNRS, INRAE, INSA, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  3. Sandrine Uttenweiler-Joseph

    Systems biology, TBI, Universite de Toulouse, CNRS, INRAE, INSA, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  4. Jean-Charles Portais

    LISBP, Université de Toulouse, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  5. Fabien Letisse

    Systems biology, TBI, Universite de Toulouse, CNRS, INRAE, INSA, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.

Funding

Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (MICA-JC)

  • Pierre Millard

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

Copyright

© 2021, Millard 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.

Metrics

  • 8,779
    views
  • 1,075
    downloads
  • 49
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Pierre Millard
  2. Brice Enjalbert
  3. Sandrine Uttenweiler-Joseph
  4. Jean-Charles Portais
  5. Fabien Letisse
(2021)
Control and regulation of acetate overflow in Escherichia coli
eLife 10:e63661.
https://doi.org/10.7554/eLife.63661

Share this article

https://doi.org/10.7554/eLife.63661

Further reading

    1. Computational and Systems Biology
    2. Microbiology and Infectious Disease
    Gaetan De Waele, Gerben Menschaert, Willem Waegeman
    Research Article

    Timely and effective use of antimicrobial drugs can improve patient outcomes, as well as help safeguard against resistance development. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently routinely used in clinical diagnostics for rapid species identification. Mining additional data from said spectra in the form of antimicrobial resistance (AMR) profiles is, therefore, highly promising. Such AMR profiles could serve as a drop-in solution for drastically improving treatment efficiency, effectiveness, and costs. This study endeavors to develop the first machine learning models capable of predicting AMR profiles for the whole repertoire of species and drugs encountered in clinical microbiology. The resulting models can be interpreted as drug recommender systems for infectious diseases. We find that our dual-branch method delivers considerably higher performance compared to previous approaches. In addition, experiments show that the models can be efficiently fine-tuned to data from other clinical laboratories. MALDI-TOF-based AMR recommender systems can, hence, greatly extend the value of MALDI-TOF MS for clinical diagnostics. All code supporting this study is distributed on PyPI and is packaged at https://github.com/gdewael/maldi-nn.

    1. Computational and Systems Biology
    2. Genetics and Genomics
    Sanjarbek Hudaiberdiev, Ivan Ovcharenko
    Research Article

    Enhancers and promoters are classically considered to be bound by a small set of transcription factors (TFs) in a sequence-specific manner. This assumption has come under increasing skepticism as the datasets of ChIP-seq assays of TFs have expanded. In particular, high-occupancy target (HOT) loci attract hundreds of TFs with often no detectable correlation between ChIP-seq peaks and DNA-binding motif presence. Here, we used a set of 1003 TF ChIP-seq datasets (HepG2, K562, H1) to analyze the patterns of ChIP-seq peak co-occurrence in combination with functional genomics datasets. We identified 43,891 HOT loci forming at the promoter (53%) and enhancer (47%) regions. HOT promoters regulate housekeeping genes, whereas HOT enhancers are involved in tissue-specific process regulation. HOT loci form the foundation of human super-enhancers and evolve under strong negative selection, with some of these loci being located in ultraconserved regions. Sequence-based classification analysis of HOT loci suggested that their formation is driven by the sequence features, and the density of mapped ChIP-seq peaks across TF-bound loci correlates with sequence features and the expression level of flanking genes. Based on the affinities to bind to promoters and enhancers we detected five distinct clusters of TFs that form the core of the HOT loci. We report an abundance of HOT loci in the human genome and a commitment of 51% of all TF ChIP-seq binding events to HOT locus formation thus challenging the classical model of enhancer activity and propose a model of HOT locus formation based on the existence of large transcriptional condensates.