A plant-like mechanism coupling m6A reading to polyadenylation safeguards transcriptome integrity and developmental gene partitioning in Toxoplasma

  1. Dayana C Farhat
  2. Matthew W Bowler
  3. Guillaume Communie
  4. Dominique Pontier
  5. Lucid Belmudes
  6. Caroline Mas
  7. Charlotte Corrao
  8. Yohann Couté
  9. Alexandre Bougdour
  10. Thierry Lagrange
  11. Mohamed-ali Hakimi  Is a corresponding author
  12. Christopher Swale  Is a corresponding author
  1. Université Grenoble Alpes, France
  2. European Molecular Biology Laboratory, France
  3. Institut Laue-Langevin, France
  4. CNRS, France

Abstract

Correct 3'end processing of mRNAs is one of the regulatory cornerstones of gene expression. In a parasite that must adapt to the regulatory requirements of its multi-host life style, there is a need to adopt additional means to partition the distinct transcriptional signatures of the closely and tandemly-arranged stage specific genes. In this study, we report our findings in T. gondii of an m6A-dependent 3'end polyadenylation serving as a transcriptional barrier at these loci. We identify the core polyadenylation complex within T. gondii and establish CPSF4 as a reader for m6A-modified mRNAs, via a YTH domain within its C-terminus, a feature which is shared with plants. We bring evidence of the specificity of this interaction both biochemically, and by determining the crystal structure at high resolution of the T. gondii CPSF4-YTH in complex with an m6A modified RNA. We show that the loss of m6A, both at the level of its deposition or its recognition was associated with an increase in aberrantly elongated chimeric mRNAs emanating from impaired transcriptional termination, a phenotype previously noticed in the plant model Arabidopsis thaliana. Nanopore direct RNA sequencing shows the occurrence of transcriptional read-through breaching into downstream repressed stage-specific genes, in the absence of either CPSF4 or the m6A RNA methylase components in both T. gondii and A. thaliana. Taken together, our results shed light on an essential regulatory mechanism coupling the pathways of m6A metabolism directly to the cleavage and polyadenylation processes, one that interestingly seem to serve, in both T. gondii and A. thaliana, as a guardian against aberrant transcriptional read-throughs.

Data availability

The Nanopore RNAseq data have been deposited in NCBI's SRA data PRJNA705300. The MS proteomics data have been deposited to the ProteomeXchange Consortium through the PRIDE partner repository with the dataset identifier PXD024326. Sequencing data have been deposited in GEO under accession code GSE168155:

The following data sets were generated

Article and author information

Author details

  1. Dayana C Farhat

    Team Host-pathogen interactions and Immunity to Infection, Université Grenoble Alpes, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
  2. Matthew W Bowler

    European Molecular Biology Laboratory, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0465-3351
  3. Guillaume Communie

    Institut Laue-Langevin, Institut Laue-Langevin, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
  4. Dominique Pontier

    UMR5096, CNRS, Perpignan, France
    Competing interests
    The authors declare that no competing interests exist.
  5. Lucid Belmudes

    BIG-BGE, Université Grenoble Alpes, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
  6. Caroline Mas

    Integrated Structural Biology Grenoble (ISBG), Université Grenoble Alpes, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
  7. Charlotte Corrao

    Team Host-pathogen interactions and Immunity to Infection, Université Grenoble Alpes, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
  8. Yohann Couté

    Institut de Biosciences et Biotechnologies de Grenoble, Université Grenoble Alpes, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3896-6196
  9. Alexandre Bougdour

    Institut de Biosciences et Biotechnologies de Grenoble, Université Grenoble Alpes, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5895-0020
  10. Thierry Lagrange

    UMR5096, CNRS, Grenoble, France
    Competing interests
    The authors declare that no competing interests exist.
  11. Mohamed-ali Hakimi

    Team Host-pathogen interactions and Immunity to Infection, Université Grenoble Alpes, Grenoble, France
    For correspondence
    mohamed-ali.hakimi@inserm.fr
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2547-8233
  12. Christopher Swale

    Team Host-pathogen interactions and Immunity to Infection, Université Grenoble Alpes, Grenoble, France
    For correspondence
    christopher.swale@univ-grenoble-alpes.fr
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9739-7774

Funding

Agence Nationale de la Recherche (Laboratoire d'Excellence (LabEx) ParaFrap [ANR-11-LABX-0024])

  • Dayana C Farhat
  • Mohamed-ali Hakimi
  • Christopher Swale

Agence Nationale de la Recherche (Project HostQuest,ANR-18-CE15-0023)

  • Charlotte Corrao
  • Alexandre Bougdour
  • Mohamed-ali Hakimi
  • Christopher Swale

European Research Council (ERC Consolidator Grant N{degree sign}614880 Hosting TOXO)

  • Mohamed-ali Hakimi

Fondation pour la Recherche Médicale (FRM FDT201904008364)

  • Dayana C Farhat
  • Mohamed-ali Hakimi

Agence Nationale de la Recherche (Proteomics French Infrastructure,Infrastructure Nationale en Biologie et Santé,ANR-10-INBS-08)

  • Lucid Belmudes
  • Yohann Couté

Agence Nationale de la Recherche (Laboratoires d'Excellences (LABEX) TULIP (ANR-10-LABX-41)")

  • Dominique Pontier
  • Thierry Lagrange

Agence Nationale de la Recherche (École Universitaire de Recherche (EUR)" TULIP-GS (ANR-18-EURE-0019)")

  • Dominique Pontier
  • Thierry Lagrange

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

Reviewing Editor

  1. Deborah Bourc'his, Institut Curie, France

Version history

  1. Preprint posted: February 23, 2021 (view preprint)
  2. Received: March 11, 2021
  3. Accepted: July 13, 2021
  4. Accepted Manuscript published: July 15, 2021 (version 1)
  5. Version of Record published: July 26, 2021 (version 2)

Copyright

© 2021, Farhat 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

  • 2,083
    Page views
  • 296
    Downloads
  • 9
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

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. Dayana C Farhat
  2. Matthew W Bowler
  3. Guillaume Communie
  4. Dominique Pontier
  5. Lucid Belmudes
  6. Caroline Mas
  7. Charlotte Corrao
  8. Yohann Couté
  9. Alexandre Bougdour
  10. Thierry Lagrange
  11. Mohamed-ali Hakimi
  12. Christopher Swale
(2021)
A plant-like mechanism coupling m6A reading to polyadenylation safeguards transcriptome integrity and developmental gene partitioning in Toxoplasma
eLife 10:e68312.
https://doi.org/10.7554/eLife.68312

Share this article

https://doi.org/10.7554/eLife.68312

Further reading

    1. Microbiology and Infectious Disease
    Chiara Andolina, Wouter Graumans ... Teun Bousema
    Research Article

    It is currently unknown whether all Plasmodium falciparum-infected mosquitoes are equally infectious. We assessed sporogonic development using cultured gametocytes in the Netherlands and naturally circulating strains in Burkina Faso. We quantified the number of sporozoites expelled into artificial skin in relation to intact oocysts, ruptured oocysts, and residual salivary gland sporozoites. In laboratory conditions, higher total sporozoite burden was associated with shorter duration of sporogony (p<0.001). Overall, 53% (116/216) of infected Anopheles stephensi mosquitoes expelled sporozoites into artificial skin with a median of 136 expelled sporozoites (interquartile range [IQR], 34–501). There was a strong positive correlation between ruptured oocyst number and salivary gland sporozoite load (ρ = 0.8; p<0.0001) and a weaker positive correlation between salivary gland sporozoite load and number of sporozoites expelled (ρ = 0.35; p=0.0002). In Burkina Faso, Anopheles coluzzii mosquitoes were infected by natural gametocyte carriers. Among salivary gland sporozoite positive mosquitoes, 89% (33/37) expelled sporozoites with a median of 1035 expelled sporozoites (IQR, 171–2969). Again, we observed a strong correlation between ruptured oocyst number and salivary gland sporozoite load (ρ = 0.9; p<0.0001) and a positive correlation between salivary gland sporozoite load and the number of sporozoites expelled (ρ = 0.7; p<0.0001). Several mosquitoes expelled multiple parasite clones during probing. Whilst sporozoite expelling was regularly observed from mosquitoes with low infection burdens, our findings indicate that mosquito infection burden is positively associated with the number of expelled sporozoites. Future work is required to determine the direct implications of these findings for transmission potential.

    1. Biochemistry and Chemical Biology
    2. Microbiology and Infectious Disease
    Veronica Teresa Ober, George Boniface Githure ... Michael Boshart
    Research Article

    Cyclic nucleotide binding domains (CNB) confer allosteric regulation by cAMP or cGMP to many signaling proteins, including PKA and PKG. PKA of phylogenetically distant Trypanosoma is the first exception as it is cyclic nucleotide-independent and responsive to nucleoside analogues (Bachmaier et al., 2019). Here, we show that natural nucleosides inosine, guanosine and adenosine are nanomolar affinity CNB ligands and activators of PKA orthologs of the important tropical pathogens Trypanosoma brucei, Trypanosoma cruzi, and Leishmania. The sequence and structural determinants of binding affinity, -specificity and kinase activation of PKAR were established by structure-activity relationship (SAR) analysis, co-crystal structures and mutagenesis. Substitution of two to three amino acids in the binding sites is sufficient for conversion of CNB domains from nucleoside to cyclic nucleotide specificity. In addition, a trypanosomatid-specific C-terminal helix (αD) is required for high affinity binding to CNB-B. The αD helix functions as a lid of the binding site that shields ligands from solvent. Selectivity of guanosine for CNB-B and of adenosine for CNB-A results in synergistic kinase activation at low nanomolar concentration. PKA pulldown from rapid lysis establishes guanosine as the predominant ligand in vivo in T. brucei bloodstream forms, whereas guanosine and adenosine seem to synergize in the procyclic developmental stage in the insect vector. We discuss the versatile use of CNB domains in evolution and recruitment of PKA for novel nucleoside-mediated signaling.