Abstract

The phylum of Apicomplexa groups intracellular parasites that employ substrate-dependent gliding motility to invade host cells, egress from the infected cells and cross biological barriers. The glideosome associated connector (GAC) is a conserved protein essential to this process. GAC facilitates the association of actin filaments with surface transmembrane adhesins and the efficient transmission of the force generated by myosin translocation of actin to the cell surface substrate. Here, we present the crystal structure of Toxoplasma gondii GAC and reveal a unique, supercoiled armadillo repeat region that adopts a closed ring conformation. Characterisation of the solution properties together with membrane and F-actin binding interfaces suggest that GAC adopts several conformations from closed to open and extended. A multi-conformational model for assembly and regulation of GAC within the glideosome is proposed.

Data availability

Diffraction data have been deposited in PDB under the accession code 8C4A.The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD039335.All data generated or analysed during this study are included in the manuscript, figures and supplementary files.

The following data sets were generated

Article and author information

Author details

  1. Amit Kumar

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  2. Oscar Vadas

    Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3511-6479
  3. Nicolas Dos Santos Pacheco

    Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1959-194X
  4. Xu Zhang

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  5. Kin Chao

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  6. Nicolas Darvill

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  7. Helena Ø Rasmussen

    Department of Chemistry, Aarhus University, Aarhus, Denmark
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8384-656X
  8. Yingqi Xu

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  9. Gloria Meng-Hsuan Lin

    Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
    Competing interests
    No competing interests declared.
  10. Fisentzos A Stylianou

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  11. Jan Skov Pedersen

    Department of Chemistry, Aarhus University, Aarhus, Denmark
    Competing interests
    No competing interests declared.
  12. Sarah L Rouse

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  13. Marc L Morgan

    Department of Life Sciences, Imperial College London, London, United Kingdom
    Competing interests
    No competing interests declared.
  14. Dominique Soldati-Favre

    Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
    Competing interests
    Dominique Soldati-Favre, Senior editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4156-2109
  15. Stephen Matthews

    Department of Life Sciences, Imperial College London, London, United Kingdom
    For correspondence
    s.j.matthews@imperial.ac.uk
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0676-0927

Funding

Leverhulme Trust (RPG_2018_107)

  • Stephen Matthews

Biotechnology and Biological Sciences Research Council (BB/W001764/1)

  • Stephen Matthews

Swiss Re Foundation (10030_185325)

  • Dominique Soldati-Favre

Swiss Re Foundation (CRSII5_198545)

  • Dominique Soldati-Favre

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

Reviewing Editor

  1. Olivier Silvie, Sorbonne Université, UPMC Univ Paris 06, INSERM, CNRS, France

Version history

  1. Received: January 10, 2023
  2. Preprint posted: January 23, 2023 (view preprint)
  3. Accepted: April 3, 2023
  4. Accepted Manuscript published: April 4, 2023 (version 1)
  5. Version of Record published: April 24, 2023 (version 2)

Copyright

© 2023, Kumar 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

  • 1,297
    Page views
  • 203
    Downloads
  • 1
    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. Amit Kumar
  2. Oscar Vadas
  3. Nicolas Dos Santos Pacheco
  4. Xu Zhang
  5. Kin Chao
  6. Nicolas Darvill
  7. Helena Ø Rasmussen
  8. Yingqi Xu
  9. Gloria Meng-Hsuan Lin
  10. Fisentzos A Stylianou
  11. Jan Skov Pedersen
  12. Sarah L Rouse
  13. Marc L Morgan
  14. Dominique Soldati-Favre
  15. Stephen Matthews
(2023)
Structural and regulatory insights into the glideosome-associated connector from Toxoplasma gondii
eLife 12:e86049.
https://doi.org/10.7554/eLife.86049

Share this article

https://doi.org/10.7554/eLife.86049

Further reading

    1. Microbiology and Infectious Disease
    Hui Han, Rong-Hua Luo ... Cheng-Gang Zou
    Research Article

    Angiotensin-converting enzyme 2 (ACE2) is a major cell entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The induction of ACE2 expression may serve as a strategy by SARS-CoV-2 to facilitate its propagation. However, the regulatory mechanisms of ACE2 expression after viral infection remain largely unknown. Using 45 different luciferase reporters, the transcription factors SP1 and HNF4α were found to positively and negatively regulate ACE2 expression, respectively, at the transcriptional level in human lung epithelial cells (HPAEpiCs). SARS-CoV-2 infection increased the transcriptional activity of SP1 while inhibiting that of HNF4α. The PI3K/AKT signaling pathway, activated by SARS-CoV-2 infection, served as a crucial regulatory node, inducing ACE2 expression by enhancing SP1 phosphorylation—a marker of its activity—and reducing the nuclear localization of HNF4α. However, colchicine treatment inhibited the PI3K/AKT signaling pathway, thereby suppressing ACE2 expression. In Syrian hamsters (Mesocricetus auratus) infected with SARS-CoV-2, inhibition of SP1 by either mithramycin A or colchicine resulted in reduced viral replication and tissue injury. In summary, our study uncovers a novel function of SP1 in the regulation of ACE2 expression and identifies SP1 as a potential target to reduce SARS-CoV-2 infection.

    1. Microbiology and Infectious Disease
    Sabrina Tetzlaff, Arne Hillebrand ... Christian Schmitz-Linneweber
    Research Article

    The mitochondrial genomes of apicomplexans comprise merely three protein-coding genes, alongside a set of thirty to forty genes encoding small RNAs (sRNAs), many of which exhibit homologies to rRNA from E. coli. The expression status and integration of these short RNAs into ribosomes remains unclear and direct evidence for active ribosomes within apicomplexan mitochondria is still lacking. In this study, we conducted small RNA sequencing on the apicomplexan Toxoplasma gondii to investigate the occurrence and function of mitochondrial sRNAs. To enhance the analysis of sRNA sequencing outcomes, we also re-sequenced the T. gondii mitochondrial genome using an improved organelle enrichment protocol and Nanopore sequencing. It has been established previously that the T. gondii genome comprises 21 sequence blocks that undergo recombination among themselves but that their order is not entirely random. The enhanced coverage of the mitochondrial genome allowed us to characterize block combinations at increased resolution. Employing this refined genome for sRNA mapping, we find that many small RNAs originated from the junction sites between protein-coding blocks and rRNA sequence blocks. Surprisingly, such block border sRNAs were incorporated into polysomes together with canonical rRNA fragments and mRNAs. In conclusion, apicomplexan ribosomes are active within polysomes and are indeed assembled through the integration of sRNAs, including previously undetected sRNAs with merged mRNA-rRNA sequences. Our findings lead to the hypothesis that T. gondii's block-based genome organization enables the dual utilization of mitochondrial sequences as both messenger RNAs and ribosomal RNAs, potentially establishing a link between the regulation of rRNA and mRNA expression.