Cryo electron tomography with Volta phase plate reveals novel structural foundations of the 96-nm axonemal repeat in the pathogen Trypanosoma brucei

  1. Simon Imhof
  2. Jiayan Zhang
  3. Hui Wang
  4. Khanh Huy Bui
  5. Hoangkim Nguyen
  6. Ivo Atanasov
  7. Wong H Hui
  8. Shun Kai Yang
  9. Z Hong Zhou  Is a corresponding author
  10. Kent L Hill  Is a corresponding author
  1. University of California, Los Angeles, United States
  2. 3640 Rue University, Canada

Abstract

The 96-nm axonemal repeat includes dynein motors and accessory structures as the foundation for motility of eukaryotic flagella and cilia. However, high-resolution 3D axoneme structures are unavailable for organisms among the Excavates, which include pathogens of medical and economic importance. Here we report cryo electron tomography structure of the 96-nm repeat from Trypanosoma brucei, a protozoan parasite in the Excavate lineage that causes African trypanosomiasis. We examined bloodstream and procyclic life cycle stages, and a knockdown lacking DRC11/CMF22 of the nexin dynein regulatory complex (NDRC). Sub-tomogram averaging yields a resolution of 21.8 Å for the 96-nm repeat. We discovered several lineage-specific structures, including novel inter-doublet linkages and microtubule inner proteins (MIPs). We establish that DRC11/CMF22 is required for the NDRC proximal lobe that binds the adjacent doublet microtubule. We propose that lineage-specific elaboration of axoneme structure in T. brucei reflects adaptations to support unique motility needs in diverse host environments.

Data availability

All data generated or analyzed during this study are included in the manuscript ans supporting files. Source data files have been provided for Figure 2F and Figure 3-Suppl. 4. The cryoET sub-tomogram average maps have been deposited in the EM Data Bank under the accession codes EMD-20012, EMD-20013 and EMD-20014, for the wild-type bloodstream form, wild-type and DRC11-knock-down procyclic form, respectively.

Article and author information

Author details

  1. Simon Imhof

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Jiayan Zhang

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Hui Wang

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Khanh Huy Bui

    Department of Anatomy and Cell Biology, 3640 Rue University, Montréal, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2814-9889
  5. Hoangkim Nguyen

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Ivo Atanasov

    California NanoSystems Institute, University of California, Los Angeles, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Wong H Hui

    California NanoSystems Institute, University of California, Los Angeles, Los Angeles, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Shun Kai Yang

    Department of Anatomy and Cell Biology, 3640 Rue University, Montréal, Canada
    Competing interests
    The authors declare that no competing interests exist.
  9. Z Hong Zhou

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
    For correspondence
    Hong.Zhou@UCLA.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8373-4717
  10. Kent L Hill

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
    For correspondence
    kenthill@microbio.ucla.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6529-1273

Funding

Swiss National Science Foundation (P300PA_174358)

  • Simon Imhof

National Science Foundation (DBI-1338135)

  • Z Hong Zhou

National Institutes of Health (R01GM071940)

  • Jiayan Zhang
  • Hui Wang
  • Wong H Hui
  • Z Hong Zhou

National Institutes of Health (S10RR23057)

  • Z Hong Zhou

National Science Foundation (DMR-1548924)

  • Z Hong Zhou

National Institutes of Health (GM007185)

  • Khanh Huy Bui

National Institutes of Health (AI052348)

  • Simon Imhof
  • Hoangkim Nguyen
  • Kent L Hill

Swiss National Science Foundation (P2BEP3_162094)

  • Simon Imhof

National Institutes of Health (S10OD018111)

  • Z Hong Zhou

National Institutes of Health (U24GM116792)

  • Z Hong Zhou

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

Reviewing Editor

  1. Andrew P Carter, MRC Laboratory of Molecular Biology, United Kingdom

Version history

  1. Received: September 20, 2019
  2. Accepted: November 11, 2019
  3. Accepted Manuscript published: November 11, 2019 (version 1)
  4. Accepted Manuscript updated: November 14, 2019 (version 2)
  5. Version of Record published: January 21, 2020 (version 3)

Copyright

© 2019, Imhof 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

  • 3,876
    views
  • 595
    downloads
  • 46
    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. Simon Imhof
  2. Jiayan Zhang
  3. Hui Wang
  4. Khanh Huy Bui
  5. Hoangkim Nguyen
  6. Ivo Atanasov
  7. Wong H Hui
  8. Shun Kai Yang
  9. Z Hong Zhou
  10. Kent L Hill
(2019)
Cryo electron tomography with Volta phase plate reveals novel structural foundations of the 96-nm axonemal repeat in the pathogen Trypanosoma brucei
eLife 8:e52058.
https://doi.org/10.7554/eLife.52058

Share this article

https://doi.org/10.7554/eLife.52058

Further reading

    1. Biochemistry and Chemical Biology
    2. Cell Biology
    Jiabin Pan, Rui Zhou ... Xiang-dong Li
    Research Article

    Transport and localization of melanosome at the periphery region of melanocyte are depended on myosin-5a (Myo5a), which associates with melanosome by interacting with its adaptor protein melanophilin (Mlph). Mlph contains four functional regions, including Rab27a-binding domain, Myo5a GTD-binding motif (GTBM), Myo5a exon F-binding domain (EFBD), and actin-binding domain (ABD). The association of Myo5a with Mlph is known to be mediated by two specific interactions: the interaction between the exon-F-encoded region of Myo5a and Mlph-EFBD and that between Myo5a-GTD and Mlph-GTBM. Here, we identify a third interaction between Myo5a and Mlph, that is, the interaction between the exon-G-encoded region of Myo5a and Mlph-ABD. The exon-G/ABD interaction is independent from the exon-F/EFBD interaction and is required for the association of Myo5a with melanosome. Moreover, we demonstrate that Mlph-ABD interacts with either the exon-G or actin filament, but cannot interact with both of them simultaneously. Based on above findings, we propose a new model for the Mlph-mediated Myo5a transportation of melanosomes.

    1. Cell Biology
    Yuhao Wang, Linhao Ruan ... Rong Li
    Research Article

    Mitochondria are the cellular energy hub and central target of metabolic regulation. Mitochondria also facilitate proteostasis through pathways such as the ‘mitochondria as guardian in cytosol’ (MAGIC) whereby cytosolic misfolded proteins (MPs) are imported into and degraded inside mitochondria. In this study, a genome-wide screen in Saccharomyces cerevisiae uncovered that Snf1, the yeast AMP-activated protein kinase (AMPK), inhibits the import of MPs into mitochondria while promoting mitochondrial biogenesis under glucose starvation. We show that this inhibition requires a downstream transcription factor regulating mitochondrial gene expression and is likely to be conferred through substrate competition and mitochondrial import channel selectivity. We further show that Snf1/AMPK activation protects mitochondrial fitness in yeast and human cells under stress induced by MPs such as those associated with neurodegenerative diseases.