1. Biochemistry and Chemical Biology
  2. Chromosomes and Gene Expression
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A mechanism for the extension and unfolding of parallel G-quadruplexes by human telomerase at single-molecule resolution

  1. Bishnu P Paudel
  2. Aaron Lavel Moye
  3. Hala Abou Assi
  4. Roberto El-Khoury
  5. Scott Cohen
  6. Jessica K Holien
  7. Monica L Birrento
  8. Siritron Samosorn
  9. Kamthorn Intharapichai
  10. Christopher G Tomlinson
  11. Marie-Paule Teulade-Fichou
  12. Carlos González
  13. Jennifer L Beck
  14. Masad J Damha
  15. Antoine M van Oijen
  16. Tracy M Bryan  Is a corresponding author
  1. University of Wollongong, Australia
  2. Children's Medical Research Institute, Australia
  3. McGill University, Canada
  4. RMIT University, Australia
  5. Srinakharinwirot University, Thailand
  6. Kyoto Institute of Technology, Japan
  7. PSL Research University, France
  8. Instituto de Química Física 'Rocasolano', Spain
Research Article
  • Cited 12
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Cite this article as: eLife 2020;9:e56428 doi: 10.7554/eLife.56428

Abstract

Telomeric G-quadruplexes (G4) were long believed to form a protective structure at telomeres, preventing their extension by the ribonucleoprotein telomerase. Contrary to this belief, we have previously demonstrated that parallel-stranded conformations of telomeric G4 can be extended by human and ciliate telomerase. However, a mechanistic understanding of the interaction of telomerase with structured DNA remained elusive. Here, we use single-molecule fluorescence resonance energy transfer (smFRET) microscopy and bulk-phase enzymology to propose a mechanism for the resolution and extension of parallel G4 by telomerase. Binding is initiated by the RNA template of telomerase interacting with the G-quadruplex; nucleotide addition then proceeds to the end of the RNA template. It is only through the large conformational change of translocation following synthesis that the G-quadruplex structure is completely unfolded to a linear product. Surprisingly, parallel G4 stabilization with either small molecule ligands or by chemical modification does not always inhibit G4 unfolding and extension by telomerase. These data reveal that telomerase is a parallel G-quadruplex resolvase.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for all summary graphs.

Article and author information

Author details

  1. Bishnu P Paudel

    School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3518-3882
  2. Aaron Lavel Moye

    Cell Biology Unit, Children's Medical Research Institute, Westmead, Australia
    Competing interests
    The authors declare that no competing interests exist.
  3. Hala Abou Assi

    Department of Chemistry, McGill University, Montreal, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1087-8805
  4. Roberto El-Khoury

    Department of Chemistry, McGill University, Montreal, Canada
    Competing interests
    The authors declare that no competing interests exist.
  5. Scott Cohen

    Cell Biology Unit, Children's Medical Research Institute, Westmead, Australia
    Competing interests
    The authors declare that no competing interests exist.
  6. Jessica K Holien

    School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
    Competing interests
    The authors declare that no competing interests exist.
  7. Monica L Birrento

    School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
    Competing interests
    The authors declare that no competing interests exist.
  8. Siritron Samosorn

    Department of Chemistry, Srinakharinwirot University, Bangkok, Thailand
    Competing interests
    The authors declare that no competing interests exist.
  9. Kamthorn Intharapichai

    Department of Biobased Materials Science, Kyoto Institute of Technology, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  10. Christopher G Tomlinson

    Cell Biology Unit, Children's Medical Research Institute, Westmead, Australia
    Competing interests
    The authors declare that no competing interests exist.
  11. Marie-Paule Teulade-Fichou

    Institut Curie, PSL Research University, Paris, France
    Competing interests
    The authors declare that no competing interests exist.
  12. Carlos González

    Instituto de Química Física 'Rocasolano', Madrid, Spain
    Competing interests
    The authors declare that no competing interests exist.
  13. Jennifer L Beck

    School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
    Competing interests
    The authors declare that no competing interests exist.
  14. Masad J Damha

    Department of Chemistry, McGill University, Montreal, Canada
    Competing interests
    The authors declare that no competing interests exist.
  15. Antoine M van Oijen

    School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, Australia
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1794-5161
  16. Tracy M Bryan

    Cell Biology Unit, Children's Medical Research Institute, Westmead, Australia
    For correspondence
    tbryan@cmri.org.au
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7990-5501

Funding

Cancer Council NSW (RG 11-07,RG 16-10)

  • Tracy M Bryan

Cancer Institute NSW

  • Aaron Lavel Moye

Australian Research Council

  • Antoine M van Oijen

Ernest and Piroska Major Foundation

  • Scott Cohen

National Science and Engineering Council

  • Masad J Damha

Centre of Excellence for Innovation in Chemistry (PERCH-CIC)

  • Siritron Samosorn

Research Unit of Natural Products and Organic Synthesis for Drug Discovery (NPOS 405/2560)

  • Siritron Samosorn

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

Reviewing Editor

  1. Sebastian Deindl, Uppsala University, Sweden

Publication history

  1. Received: February 28, 2020
  2. Accepted: July 28, 2020
  3. Accepted Manuscript published: July 29, 2020 (version 1)
  4. Version of Record published: August 13, 2020 (version 2)

Copyright

© 2020, Paudel 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.

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