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


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.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Change history

  • 31 July 2014

    A panel label in Fig. 2e has been corrected


  1. 1.

    & Plasmodium nesting: remaking the erythrocyte from the inside out. Annu. Rev. Microbiol. 67, 243–269 (2013)

  2. 2.

    et al. A newly discovered protein export machine in malaria parasites. Nature 459, 945–949 (2009)

  3. 3.

    et al. Biosynthesis, localization, and macromolecular arrangement of the Plasmodium falciparum translocon of exported proteins (PTEX). J. Biol. Chem. 287, 7871–7884 (2012)

  4. 4.

    et al. Spatial association with PTEX complexes defines regions for effector export into Plasmodium falciparum-infected erythrocytes. Nature Commun. 4, 1415 (2013)

  5. 5.

    , , , & A general chemical method to regulate protein stability in the mammalian central nervous system. Chem. Biol. 17, 981–988 (2010)

  6. 6.

    , , , & Asparagine repeat function in a Plasmodium falciparum protein assessed via a regulatable fluorescent affinity tag. Proc. Natl Acad. Sci. USA 108, 4411–4416 (2011)

  7. 7.

    , , , & Plasmodium falciparum heat shock protein 110 stabilizes the asparagine repeat-rich parasite proteome during malarial fevers. Nature Commun. 3, 1310 (2012)

  8. 8.

    et al. Protein export marks the early phase of gametocytogenesis of the human malaria parasite Plasmodium falciparum. Mol. Cell. Proteomics 9, 1437–1448 (2010)

  9. 9.

    et al. The Plasmodium translocon of exported proteins (PTEX) component thioredoxin-2 is important for maintaining normal blood-stage growth. Mol. Microbiol. 89, 1167–1186 (2013)

  10. 10.

    , , , & Targeting malaria virulence and remodeling proteins to the host erythrocyte. Science 306, 1930–1933 (2004)

  11. 11.

    et al. A host-targeting signal in virulence proteins reveals a secretome in malarial infection. Science 306, 1934–1937 (2004)

  12. 12.

    et al. Plasmepsin V licenses Plasmodium proteins for export into the host erythrocyte. Nature 463, 632–636 (2010)

  13. 13.

    et al. An aspartyl protease directs malaria effector proteins to the host cell. Nature 463, 627–631 (2010)

  14. 14.

    et al. Comparative analysis of the Plasmodium falciparum histidine-rich proteins HRP-I, HRP-II and HRP-III in malaria parasites of diverse origin. Parasitology 95, 209–227 (1987)

  15. 15.

    et al. A cluster of ring stage-specific genes linked to a locus implicated in cytoadherence in Plasmodium falciparum codes for PEXEL-negative and PEXEL-positive proteins exported into the host cell. Mol. Biol. Cell 17, 3613–3624 (2006)

  16. 16.

    et al. Targeted gene disruption shows that knobs enable malaria-infected red cells to cytoadhere under physiological shear stress. Cell 89, 287–296 (1997)

  17. 17.

    , & Plasmodium falciparum ring-infected erythrocyte surface antigen is released from merozoite dense granules after erythrocyte invasion. Infect. Immun. 59, 1183–1187 (1991)

  18. 18.

    et al. Role of plasmepsin V in export of diverse protein families from the Plasmodium falciparum exportome. Traffic 14, 532–550 (2013)

  19. 19.

    et al. Uncovering common principles in protein export of malaria parasites. Cell Host Microbe 12, 717–729 (2012)

  20. 20.

    & Maurer's clefts, the enigma of Plasmodium falciparum. Proc. Natl Acad. Sci. USA 110, 19987–19994 (2013)

  21. 21.

    et al. Pfsbp1, a Maurer’s cleft Plasmodium falciparum protein, is associated with the erythrocyte skeleton. Mol. Biochem. Parasitol. 111, 107–121 (2000)

  22. 22.

    et al. Identification of new PNEPs indicates a substantial non-PEXEL exportome and underpins common features in Plasmodium falciparum protein export. PLoS Pathog. 9, e1003546 (2013)

  23. 23.

    , , & The pathogenic basis of malaria. Nature 415, 673–679 (2002)

  24. 24.

    et al. Parasite-encoded Hsp40 proteins define novel mobile structures in the cytosol of the P. falciparum-infected erythrocyte. Cell. Microbiol. 12, 1398–1420 (2010)

  25. 25.

    , , & Trafficking of plasmepsin II to the food vacuole of the malaria parasite Plasmodium falciparum. J. Cell Biol. 164, 47–56 (2004)

  26. 26.

    et al. Subcellular discharge of a serine protease mediates release of invasive malaria parasites from host erythrocytes. Cell 131, 1072–1083 (2007)

  27. 27.

    et al. Functional analysis of the exported type IV HSP40 protein PfGECO in Plasmodium falciparum gametocytes. Eukaryot. Cell 10, 1492–1503 (2011)

  28. 28.

    et al. Malaria parasite clag3 genes determine channel-mediated nutrient uptake by infected red blood cells. Cell 145, 665–677 (2011)

  29. 29.

    , , , & Export of a Toxoplasma gondii rhoptry neck protein complex at the host cell membrane to form the moving junction during invasion. PLoS Pathog. 5, e1000309 (2009)

  30. 30.

    et al. Selective permeabilization of the host cell membrane of Plasmodium falciparum-infected red blood cells with streptolysin O and equinatoxin II. Biochem. J. 403, 167–175 (2007)

  31. 31.

    , , & The role of Plasmodium falciparum food vacuole plasmepsins. J. Biol. Chem. 280, 1432–1437 (2005)

  32. 32.

    , , & High-efficiency transformation of Plasmodium falciparum by the lepidopteran transposable element piggyBac. Proc. Natl Acad. Sci. USA 102, 16391–16396 (2005)

  33. 33.

    et al. Antigens of the erythrocytes stages of the human malaria parasite Plasmodium falciparum detected by monoclonal antibodies. Mol. Biochem. Parasitol. 7, 247–265 (1983)

  34. 34.

    et al. in Molecular Strategies of Parasitic Invasion (eds , & ) 333–342 (Alan R. Liss, 1987)

  35. 35.

    , , , & Induction and localization of Plasmodium falciparum stress proteins related to the heat shock protein 70 family. Mol. Biochem. Parasitol. 48, 47–58 (1991)

  36. 36.

    et al. A novel Plasmodium falciparum ring stage protein, REX, is located in Maurer’s clefts. Mol. Biochem. Parasitol. 136, 181–189 (2004)

  37. 37.

    et al. Identification of a subtelomeric gene family expressed during the asexual-sexual stage transition in Plasmodium falciparum. Mol. Biochem. Parasitol. 143, 90–99 (2005)

  38. 38.

    et al. Serum lipoproteins promote efficient presentation of the malaria virulence protein PfEMP1 at the erythrocyte surface. Eukaryot. Cell 6, 1584–1594 (2007)

  39. 39.

    , & Biosynthesis and maturation of the malaria aspartic hemoglobinases plasmepsins I and II. J. Biol. Chem. 272, 14961–14968 (1997)

  40. 40.

    et al. In vitro biosynthesis and membrane translocation of the serine rich protein of Plasmodium falciparum. Mol. Biochem. Parasitol. 42, 93–100 (1990)

  41. 41.

    & Imaging of live malaria blood stage parasites. Methods Enzymol. 506, 81–92 (2012)

  42. 42.

    , , & Characterization of permeation pathways appearing in the host membrane of Plasmodium falciparum infected red blood cells. Mol. Biochem. Parasitol. 14, 313–322 (1985)

  43. 43.

    , , , & Transport of diverse substrates into malaria-infected erythrocytes via a pathway showing functional characteristics of a chloride channel. J. Biol. Chem. 269, 3339–3347 (1994)

  44. 44.

    et al. Plasmodium falciparum responds to amino acid starvation by entering into a hibernatory state. Proc. Natl Acad. Sci. USA 109, E3278–E3287 (2012)

Download references


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.


  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


  1. Search for Josh R. Beck in:

  2. Search for Vasant Muralidharan in:

  3. Search for Anna Oksman in:

  4. Search for Daniel E. Goldberg in:


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.

Extended data

About this article

Publication history







By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.