Letter | Published:

PTEX component HSP101 mediates export of diverse malaria effectors into host erythrocytes

Nature volume 511, pages 592595 (31 July 2014) | Download Citation

This article has been updated

Abstract

To mediate its survival and virulence, the malaria parasite Plasmodium falciparum exports hundreds of proteins into the host erythrocyte1. To enter the host cell, exported proteins must cross the parasitophorous vacuolar membrane (PVM) within which the parasite resides, but the mechanism remains unclear. A putative Plasmodium translocon of exported proteins (PTEX) has been suggested to be involved for at least one class of exported proteins; however, direct functional evidence for this has been elusive2,3,4. Here we show that export across the PVM requires heat shock protein 101 (HSP101), a ClpB-like AAA+ ATPase component of PTEX. Using a chaperone auto-inhibition strategy, we achieved rapid, reversible ablation of HSP101 function, resulting in a nearly complete block in export with substrates accumulating in the vacuole in both asexual and sexual parasites. Surprisingly, this block extended to all classes of exported proteins, revealing HSP101-dependent translocation across the PVM as a convergent step in the multi-pathway export process. Under export-blocked conditions, association between HSP101 and other components of the PTEX complex was lost, indicating that the integrity of the complex is required for efficient protein export. Our results demonstrate an essential and universal role for HSP101 in protein export and provide strong evidence for PTEX function in protein translocation into the host cell.

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Change history

  • 31 July 2014

    A panel label in Fig. 2e has been corrected

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Acknowledgements

This work was supported by National Institutes of Health grants AI047798 to D.E.G., T32-AI007172 to J.R.B. and AI099156 to V.M. We thank J. McBride, D. Cavanagh and EMRR for anti-EXP2 antibody, J. Adams and ATCC (MR4) for anti-BiP antibody, D. Taylor for anti-HRP2 antibody, R. Anders for anti-RESA antibody, C. Braun-Breton for anti-SBP1 antibody, K. Williamson for anti-PfGECO and anti-Pfs16 antibodies, T. Spielmann for anti-REX2, anti-REX3 and anti-MSRP6 antibodies, L. Tilley for anti-REX1 and anti-PfEMP1 antibodies, S. Desai for anti-CLAG3 antibody, A. Cowman for anti-KAHRP antibody, J. Przyborski and K. Lingelbach for anti-SERP antibody, W. Beatty for assistance with electron microscopy, B. Vaupel and T. Butler for technical assistance and P. Sigala and N. Spillman for suggestions.

Author information

Author notes

    • Josh R. Beck
    •  & Vasant Muralidharan

    These authors contributed equally to this work.

    • Vasant Muralidharan

    Present address: Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, USA.

Affiliations

  1. Department of Molecular Microbiology, Washington University School of Medicine, St Louis, Missouri 63110, USA

    • Josh R. Beck
    • , Anna Oksman
    •  & Daniel E. Goldberg
  2. Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA

    • Vasant Muralidharan
    • , Anna Oksman
    •  & Daniel E. Goldberg
  3. Howard Hughes Medical Institute, Washington University School of Medicine, St Louis, Missouri 63110, USA

    • Vasant Muralidharan
    • , Anna Oksman
    •  & Daniel E. Goldberg

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Contributions

J.R.B., V.M. and D.E.G. conceived and designed experiments. J.R.B. performed the majority of the experiments and V.M. performed some experiments. V.M. and A.O. generated the HSP101DDD strains. J.R.B and A.O. performed the gametocyte analysis. J.R.B. and D.E.G. analysed the data and wrote the manuscript. All authors discussed and edited the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Daniel E. Goldberg.

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DOI

https://doi.org/10.1038/nature13574

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