Formin-2 drives polymerisation of actin filaments enabling segregation of apicoplasts and cytokinesis in Plasmodium falciparum

  1. Johannes Felix Stortz
  2. Mario Del Rosario
  3. Mirko Singer
  4. Jonathan M Wilkes
  5. Markus Meissner  Is a corresponding author
  6. Sujaan Das  Is a corresponding author
  1. University of Glasgow, United Kingdom
  2. Ludwig-Maximillians University, Germany

Abstract

Plasmodium falciparum actin, apart from its role in erythrocyte invasion, is implicated in endocytosis, cytokinesis and inheritance of the chloroplast-like organelle - the apicoplast. However, the inability to visualise filamentous actin (F-actin) dynamics, a limitation we recently overcame for Toxoplasma (Periz et al, 2017), restricted characterisation of both F-actin and actin regulatory proteins. Here, we expressed and validated actin-binding chromobodies as F-actin-sensors in Plasmodium falciparum and characterised in-vivo actin dynamics. F-actin could be chemically modulated, and genetically disrupted upon conditionally deleting actin-1. In a comparative approach, we demonstrate that Formin-2, a predicted nucleator of F-actin, is responsible for apicoplast inheritance in both Plasmodium and Toxoplasma, and additionally mediates efficient cytokinesis in Plasmodium. Finally, time-averaged local intensity measurements of F-actin in Toxoplasma conditional mutants revealed molecular determinants of spatiotemporally regulated F-actin flow. Together, our data indicate that Formin-2 is the primary F-actin nucleator during apicomplexan intracellular growth, mediating multiple essential functions.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Proteomes of interest (Supplementary File 2) were downloaded from the UniProt-KB website (www.uniprot.org).

Article and author information

Author details

  1. Johannes Felix Stortz

    Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  2. Mario Del Rosario

    Division of Infection and Immunity, Institute of Biomedical Life Sciences, University of Glasgow, Glasgow, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0430-1463
  3. Mirko Singer

    Faculty of Veterinary Medicine, Ludwig-Maximillians University, Munich, Germany
    Competing interests
    The authors declare that no competing interests exist.
  4. Jonathan M Wilkes

    Wellcome Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
  5. Markus Meissner

    Faculty of Veterinary Medicine, Ludwig-Maximillians University, Munich, Germany
    For correspondence
    Markus.Meissner@para.vetmed.uni-muenchen.de
    Competing interests
    The authors declare that no competing interests exist.
  6. Sujaan Das

    Faculty of Veterinary Medicine, Ludwig-Maximillians University, Munich, Germany
    For correspondence
    Sujaan.Das@para.vetmed.uni-muenchen.de
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6466-4258

Funding

H2020 Excellent Science (ERC-2012-StG 309255-EndoTox)

  • Markus Meissner

Wellcome (Wellcome Senior Fellowship 103875/Z/14/Z)

  • Markus Meissner

Horizon 2020 Framework Programme (LMU Fellowship H2020-MSCA-COFUND-2016-754388)

  • Sujaan Das

Wellcome (085349 - Core funding for the WCMP)

  • Johannes Felix Stortz
  • Mario Del Rosario
  • Jonathan M Wilkes
  • Markus Meissner
  • Sujaan Das

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

Copyright

© 2019, Felix Stortz 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

  • 3,246
    views
  • 418
    downloads
  • 39
    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. Johannes Felix Stortz
  2. Mario Del Rosario
  3. Mirko Singer
  4. Jonathan M Wilkes
  5. Markus Meissner
  6. Sujaan Das
(2019)
Formin-2 drives polymerisation of actin filaments enabling segregation of apicoplasts and cytokinesis in Plasmodium falciparum
eLife 8:e49030.
https://doi.org/10.7554/eLife.49030

Share this article

https://doi.org/10.7554/eLife.49030

Further reading

    1. Microbiology and Infectious Disease
    Edited by Olivier Silvie et al.
    Collection

    eLife has recently published a wide range of papers on malaria, covering a diversity of themes including parasite biology, epidemiology, immunology, drugs and vaccines.

    1. Cancer Biology
    2. Cell Biology
    Ida Marie Boisen, Nadia Krarup Knudsen ... Martin Blomberg Jensen
    Research Article

    Testicular microcalcifications consist of hydroxyapatite and have been associated with an increased risk of testicular germ cell tumors (TGCTs) but are also found in benign cases such as loss-of-function variants in the phosphate transporter SLC34A2. Here, we show that fibroblast growth factor 23 (FGF23), a regulator of phosphate homeostasis, is expressed in testicular germ cell neoplasia in situ (GCNIS), embryonal carcinoma (EC), and human embryonic stem cells. FGF23 is not glycosylated in TGCTs and therefore cleaved into a C-terminal fragment which competitively antagonizes full-length FGF23. Here, Fgf23 knockout mice presented with marked calcifications in the epididymis, spermatogenic arrest, and focally germ cells expressing the osteoblast marker Osteocalcin (gene name: Bglap, protein name). Moreover, the frequent testicular microcalcifications in mice with no functional androgen receptor and lack of circulating gonadotropins are associated with lower Slc34a2 and higher Bglap/Slc34a1 (protein name: NPT2a) expression compared with wild-type mice. In accordance, human testicular specimens with microcalcifications also have lower SLC34A2 and a subpopulation of germ cells express phosphate transporter NPT2a, Osteocalcin, and RUNX2 highlighting aberrant local phosphate handling and expression of bone-specific proteins. Mineral disturbance in vitro using calcium or phosphate treatment induced deposition of calcium phosphate in a spermatogonial cell line and this effect was fully rescued by the mineralization inhibitor pyrophosphate. In conclusion, testicular microcalcifications arise secondary to local alterations in mineral homeostasis, which in combination with impaired Sertoli cell function and reduced levels of mineralization inhibitors due to high alkaline phosphatase activity in GCNIS and TGCTs facilitate osteogenic-like differentiation of testicular cells and deposition of hydroxyapatite.