Skip to main content
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Accessibility Statement
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian
  • Log in
  • My Cart

Main menu

  • Home
  • Articles
    • Current
    • Special Feature Articles - Most Recent
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • List of Issues
  • Front Matter
  • News
    • For the Press
    • This Week In PNAS
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Editorial and Journal Policies
    • Submission Procedures
    • Fees and Licenses
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Accessibility Statement
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian

User menu

  • Log in
  • My Cart

Search

  • Advanced search
Home
Home

Advanced Search

  • Home
  • Articles
    • Current
    • Special Feature Articles - Most Recent
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • List of Issues
  • Front Matter
  • News
    • For the Press
    • This Week In PNAS
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Editorial and Journal Policies
    • Submission Procedures
    • Fees and Licenses

New Research In

Physical Sciences

Featured Portals

  • Physics
  • Chemistry
  • Sustainability Science

Articles by Topic

  • Applied Mathematics
  • Applied Physical Sciences
  • Astronomy
  • Computer Sciences
  • Earth, Atmospheric, and Planetary Sciences
  • Engineering
  • Environmental Sciences
  • Mathematics
  • Statistics

Social Sciences

Featured Portals

  • Anthropology
  • Sustainability Science

Articles by Topic

  • Economic Sciences
  • Environmental Sciences
  • Political Sciences
  • Psychological and Cognitive Sciences
  • Social Sciences

Biological Sciences

Featured Portals

  • Sustainability Science

Articles by Topic

  • Agricultural Sciences
  • Anthropology
  • Applied Biological Sciences
  • Biochemistry
  • Biophysics and Computational Biology
  • Cell Biology
  • Developmental Biology
  • Ecology
  • Environmental Sciences
  • Evolution
  • Genetics
  • Immunology and Inflammation
  • Medical Sciences
  • Microbiology
  • Neuroscience
  • Pharmacology
  • Physiology
  • Plant Biology
  • Population Biology
  • Psychological and Cognitive Sciences
  • Sustainability Science
  • Systems Biology
Research Article

Parasitophorous vacuole poration precedes its rupture and rapid host erythrocyte cytoskeleton collapse in Plasmodium falciparum egress

Victoria L. Hale, Jean M. Watermeyer, Fiona Hackett, Gema Vizcay-Barrena, Christiaan van Ooij, James A. Thomas, Matthew C. Spink, Maria Harkiolaki, Elizabeth Duke, Roland A. Fleck, Michael J. Blackman, and Helen R. Saibil
PNAS March 28, 2017 114 (13) 3439-3444; first published March 14, 2017; https://doi.org/10.1073/pnas.1619441114
Victoria L. Hale
aCrystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 7HX, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Jean M. Watermeyer
aCrystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 7HX, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Fiona Hackett
bFrancis Crick Institute, London, NW1 1AT, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Gema Vizcay-Barrena
cCentre for Ultrastructural Imaging, Kings College London, London, SE1 9RT, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Christiaan van Ooij
bFrancis Crick Institute, London, NW1 1AT, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
James A. Thomas
bFrancis Crick Institute, London, NW1 1AT, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Matthew C. Spink
dDiamond Light Source, Didcot, OX11 0DE, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Maria Harkiolaki
dDiamond Light Source, Didcot, OX11 0DE, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Elizabeth Duke
dDiamond Light Source, Didcot, OX11 0DE, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Roland A. Fleck
cCentre for Ultrastructural Imaging, Kings College London, London, SE1 9RT, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Michael J. Blackman
bFrancis Crick Institute, London, NW1 1AT, United Kingdom;
eFaculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Helen R. Saibil
aCrystallography, Institute of Structural and Molecular Biology, Birkbeck College, London, WC1E 7HX, United Kingdom;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • For correspondence: h.saibil@mail.cryst.bbk.ac.uk
  1. Edited by John C. Boothroyd, Stanford University Medical Center, Stanford, CA, and approved February 15, 2017 (received for review December 1, 2016)

  • Article
  • Figures & SI
  • Info & Metrics
  • PDF
Loading

Significance

Malaria parasites develop within red blood cells inside a membrane-enclosed parasitophorous vacuole. An essential step in their life cycle is the exit of mature parasites from the blood cell, a multistage process termed egress. To do this, the parasites orchestrate a highly regulated sequence of membrane permeabilization and breakage steps culminating in the explosive release of parasites for a new round of infection. Here, we describe a previously unidentified permeabilization of the vacuolar membrane at the start of egress, preceding membrane rupture, suggesting a new initiation step in egress. We also show that, in the final minutes of egress, the blood cell membrane abruptly loses its structural rigidity and collapses around the parasites, showing a precise timing for cytoskeletal breakdown.

Abstract

In the asexual blood stages of malarial infection, merozoites invade erythrocytes and replicate within a parasitophorous vacuole to form daughter cells that eventually exit (egress) by sequential rupture of the vacuole and erythrocyte membranes. The current model is that PKG, a malarial cGMP-dependent protein kinase, triggers egress, activating malarial proteases and other effectors. Using selective inhibitors of either PKG or cysteine proteases to separately inhibit the sequential steps in membrane perforation, combined with video microscopy, electron tomography, electron energy loss spectroscopy, and soft X-ray tomography of mature intracellular Plasmodium falciparum parasites, we resolve intermediate steps in egress. We show that the parasitophorous vacuole membrane (PVM) is permeabilized 10–30 min before its PKG-triggered breakdown into multilayered vesicles. Just before PVM breakdown, the host red cell undergoes an abrupt, dramatic shape change due to the sudden breakdown of the erythrocyte cytoskeleton, before permeabilization and eventual rupture of the erythrocyte membrane to release the parasites. In contrast to the previous view of PKG-triggered initiation of egress and a gradual dismantling of the host erythrocyte cytoskeleton over the course of schizont development, our findings identify an initial step in egress and show that host cell cytoskeleton breakdown is restricted to a narrow time window within the final stages of egress.

  • malaria
  • egress
  • electron tomography
  • soft X-ray microscopy
  • electron energy loss spectroscopy

Footnotes

  • ↵1Present address: Pinelands High School, Pinelands, 7405, South Africa.

  • ↵2To whom correspondence should be addressed. Email: h.saibil{at}mail.cryst.bbk.ac.uk.
  • Author contributions: R.A.F., M.J.B., and H.R.S. designed research; V.L.H., J.M.W., F.H., G.V.-B., C.v.O., J.A.T., M.C.S., and M.H. performed research; E.D. contributed new reagents/analytic tools; V.L.H. analyzed data; and V.L.H., M.J.B., and H.R.S. wrote the paper.

  • The authors declare no conflict of interest.

  • This article is a PNAS Direct Submission.

  • Data deposition: The data reported in this paper have been deposited in the EM Database for EM tomograms (accession nos. EMD-3586, EMD-3587, EMD-3606, and EMD-3610) and EMPIAR for X-ray tomograms (accession no. EMPIAR-10087).

  • This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1619441114/-/DCSupplemental.

Freely available online through the PNAS open access option.

View Full Text
PreviousNext
Back to top
Article Alerts
Email Article

Thank you for your interest in spreading the word on PNAS.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Parasitophorous vacuole poration precedes its rupture and rapid host erythrocyte cytoskeleton collapse in Plasmodium falciparum egress
(Your Name) has sent you a message from PNAS
(Your Name) thought you would like to see the PNAS web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Sequence of steps in malaria parasite egress
Victoria L. Hale, Jean M. Watermeyer, Fiona Hackett, Gema Vizcay-Barrena, Christiaan van Ooij, James A. Thomas, Matthew C. Spink, Maria Harkiolaki, Elizabeth Duke, Roland A. Fleck, Michael J. Blackman, Helen R. Saibil
Proceedings of the National Academy of Sciences Mar 2017, 114 (13) 3439-3444; DOI: 10.1073/pnas.1619441114

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Request Permissions
Share
Sequence of steps in malaria parasite egress
Victoria L. Hale, Jean M. Watermeyer, Fiona Hackett, Gema Vizcay-Barrena, Christiaan van Ooij, James A. Thomas, Matthew C. Spink, Maria Harkiolaki, Elizabeth Duke, Roland A. Fleck, Michael J. Blackman, Helen R. Saibil
Proceedings of the National Academy of Sciences Mar 2017, 114 (13) 3439-3444; DOI: 10.1073/pnas.1619441114
Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Mendeley logo Mendeley
Proceedings of the National Academy of Sciences: 114 (13)
Table of Contents

Submit

Sign up for Article Alerts

Article Classifications

  • Biological Sciences
  • Cell Biology

Jump to section

  • Article
    • Abstract
    • Results
    • Discussion
    • Methods
    • SI Methods
    • Acknowledgments
    • Footnotes
    • References
  • Figures & SI
  • Info & Metrics
  • PDF

You May Also be Interested in

Abstract depiction of a guitar and musical note
Science & Culture: At the nexus of music and medicine, some see disease treatments
Although the evidence is still limited, a growing body of research suggests music may have beneficial effects for diseases such as Parkinson’s.
Image credit: Shutterstock/agsandrew.
Large piece of gold
News Feature: Tracing gold's cosmic origins
Astronomers thought they’d finally figured out where gold and other heavy elements in the universe came from. In light of recent results, they’re not so sure.
Image credit: Science Source/Tom McHugh.
Dancers in red dresses
Journal Club: Friends appear to share patterns of brain activity
Researchers are still trying to understand what causes this strong correlation between neural and social networks.
Image credit: Shutterstock/Yeongsik Im.
White and blue bird
Hazards of ozone pollution to birds
Amanda Rodewald, Ivan Rudik, and Catherine Kling talk about the hazards of ozone pollution to birds.
Listen
Past PodcastsSubscribe
Goats standing in a pin
Transplantation of sperm-producing stem cells
CRISPR-Cas9 gene editing can improve the effectiveness of spermatogonial stem cell transplantation in mice and livestock, a study finds.
Image credit: Jon M. Oatley.

Similar Articles

Site Logo
Powered by HighWire
  • Submit Manuscript
  • Twitter
  • Facebook
  • RSS Feeds
  • Email Alerts

Articles

  • Current Issue
  • Special Feature Articles – Most Recent
  • List of Issues

PNAS Portals

  • Anthropology
  • Chemistry
  • Classics
  • Front Matter
  • Physics
  • Sustainability Science
  • Teaching Resources

Information

  • Authors
  • Editorial Board
  • Reviewers
  • Librarians
  • Press
  • Site Map
  • PNAS Updates

Feedback    Privacy/Legal

Copyright © 2021 National Academy of Sciences. Online ISSN 1091-6490