1. Cell Biology
  2. Developmental Biology
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Chlamydomonas ARMC2/PF27 is an obligate cargo adapter for IFT of radial spokes

  1. Karl F Lechtreck  Is a corresponding author
  2. Yi Liu
  3. Jin Dai
  4. Rama A Alkhofash
  5. jack Butler
  6. Lea Alford
  7. Pinfen Yang  Is a corresponding author
  1. University of Georgia, United States
  2. Marquette University, United States
  3. Oglethorpe University, United States
Research Article
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Cite this article as: eLife 2022;11:e74993 doi: 10.7554/eLife.74993

Abstract

Intraflagellar transport (IFT) carries proteins into flagella but how IFT trains interact with the large number of diverse proteins required to assemble flagella remains largely unknown. Here, we show that IFT of radial spokes in Chlamydomonas requires ARMC2/PF27, a conserved armadillo repeat protein associated with male infertility and reduced lung function. Chlamydomonas ARMC2 was highly enriched in growing flagella and tagged ARMC2 and the spoke protein RSP3 comigrated on anterograde trains. In contrast, a cargo and an adapter of inner and outer dynein arms moved independently of ARMC2, indicating that unrelated cargoes distribute stochastically onto the IFT trains. After concomitant unloading at the flagellar tip, RSP3 attached to the axoneme whereas ARMC2 diffused back to the cell body. In armc2/pf27 mutants, IFT of radial spokes was abolished and the presence of radial spokes was limited to the proximal region of flagella. We conclude that ARMC2 is a cargo adapter required for IFT of radial spokes to ensure their assembly along flagella. ARMC2 belongs to a growing class of cargo-specific adapters that enable flagellar transport of preassembled axonemal substructures by IFT.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting file; Source Data files have been provided for the western blots in Figures 1, 2, Figure 1 -Supplement 1 and Figure 2 - Supplement 1.

Article and author information

Author details

  1. Karl F Lechtreck

    Department of Cellular Biology, University of Georgia, Athens, United States
    For correspondence
    lechtrek@uga.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6219-6470
  2. Yi Liu

    Department of Biological Sciences, Marquette University, Milwaukee, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Jin Dai

    Department of Cellular Biology, University of Georgia, Athens, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Rama A Alkhofash

    Department of Cellular Biology, University of Georgia, Athens, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. jack Butler

    Department of Cellular Biology, University of Georgia, Athens, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Lea Alford

    Division of Natural Sciences,, Oglethorpe University, Atlanta, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Pinfen Yang

    Department of Biological Sciences, Marquette University, Milwaukee, United States
    For correspondence
    pinfen.yang@marquette.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3773-0053

Funding

National Institute of Health (R01GM110413)

  • Karl F Lechtreck

NIH (R015GM12813)

  • Lea Alford
  • Pinfen Yang

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Reviewing Editor

  1. Lotte B Pedersen, University of Copenhagen, Denmark

Publication history

  1. Received: October 25, 2021
  2. Accepted: January 3, 2022
  3. Accepted Manuscript published: January 4, 2022 (version 1)

Copyright

© 2022, Lechtreck 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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