1. Cell Biology

A liquid-like organelle at the root of motile ciliopathy

  1. Ryan L Huizar
  2. Chanjae Lee
  3. Alexander A Boulgakov
  4. Amjad Horani
  5. Fan Tu
  6. Edward M Marcotte
  7. Steven L Brody
  8. John B Wallingford  Is a corresponding author
  1. University of Texas at Austin, United States
  2. Washington University School of Medicine, United States
https://doi.org/10.7554/eLife.38497
Share this article
Cite this article
  1. Ryan L Huizar
  2. Chanjae Lee
  3. Alexander A Boulgakov
  4. Amjad Horani
  5. Fan Tu
  6. Edward M Marcotte
  7. Steven L Brody
  8. John B Wallingford
(2018)
A liquid-like organelle at the root of motile ciliopathy
eLife 7:e38497.
https://doi.org/10.7554/eLife.38497
  2. Download BibTeX
  3. Download .RIS

Abstract

Motile ciliopathies are characterized by specific defects in cilia beating that result in chronic airway disease, subfertility, ectopic pregnancy, and hydrocephalus. While many patients harbor mutations in the dynein motors that drive cilia beating, the disease also results from mutations in so-called Dynein Axonemal Assembly Factors (DNAAFs) that act in the cytoplasm. The mechanisms of DNAAF action remain poorly defined. Here, we show that DNAAFs concentrate together with axonemal dyneins and chaperones into organelles that form specifically in multiciliated cells, which we term DynAPs, for Dynein Axonemal Particles. These organelles display hallmarks of biomolecular condensates, and remarkably, DynAPs are enriched for the stress granule protein G3bp1, but not for other stress granule proteins or P-body proteins. Finally, we show that both the formation and the liquid-like behaviors of DynAPs are disrupted in a model of motile ciliopathy. These findings provide a unifying cell biological framework for a poorly understood class of human disease genes and add motile ciliopathy to the growing roster of human diseases associated with disrupted biological phase separation.

Data availability

Software has been deposited to GitHub (https://github.com/marcottelab/FociFinder3D) and image data will be uploaded to Dryad.

Article and author information

Author details

  1. Ryan L Huizar

    Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
    Competing interests
    The authors declare that no competing interests exist.

  2. Chanjae Lee

    Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Alexander A Boulgakov

    Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7446-1120

  4. Amjad Horani

    Department of Pediatrics, Washington University School of Medicine, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.

  5. Fan Tu

    Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
    Competing interests
    The authors declare that no competing interests exist.

  6. Edward M Marcotte

    Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8808-180X

  7. Steven L Brody

    Department of Medicine, Washington University School of Medicine, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.

  8. John B Wallingford

    Department of Molecular Biosciences, University of Texas at Austin, Austin, United States
    For correspondence
    wallingford@austin.utexas.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6280-8625

Funding

National Heart, Lung, and Blood Institute

  • Ryan L Huizar
  • Chanjae Lee
  • John B Wallingford

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

Ethics

Animal experimentation: Work here was approved by the UT Austin IACUC under protocol numbers: AUP-2015-00160 and AUP-2016-00184.

Copyright

© 2018, Huizar 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

  • 4,162
    views
  • 771
    downloads
  • 57
    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. Ryan L Huizar
  2. Chanjae Lee
  3. Alexander A Boulgakov
  4. Amjad Horani
  5. Fan Tu
  6. Edward M Marcotte
  7. Steven L Brody
  8. John B Wallingford
(2018)
A liquid-like organelle at the root of motile ciliopathy
eLife 7:e38497.
https://doi.org/10.7554/eLife.38497

Share this article

https://doi.org/10.7554/eLife.38497

Categories and tags

Research organism

Further reading

    1. Cell Biology

    Ezrin defines TSC complex activation at endosomal compartments through EGFR–AKT signaling

    Giuliana Giamundo, Daniela Intartaglia ... Ivan Conte
    Research Article

    Endosomes have emerged as major signaling hubs where different internalized ligand–receptor complexes are integrated and the outcome of signaling pathways are organized to regulate the strength and specificity of signal transduction events. Ezrin, a major membrane–actin linker that assembles and coordinates macromolecular signaling complexes at membranes, has emerged recently as an important regulator of lysosomal function. Here, we report that endosomal-localized EGFR/Ezrin complex interacts with and triggers the inhibition of the Tuberous Sclerosis Complex (TSC complex) in response to EGF stimuli. This is regulated through activation of the AKT signaling pathway. Loss of Ezrin was not sufficient to repress TSC complex by EGF and culminated in translocation of TSC complex to lysosomes triggering suppression of mTORC1 signaling. Overexpression of constitutively active EZRINT567D is sufficient to relocalize TSC complex to the endosomes and reactivate mTORC1. Our findings identify EZRIN as a critical regulator of autophagy via TSC complex in response to EGF stimuli and establish the central role of early endosomal signaling in the regulation of mTORC1. Consistently, Medaka fish deficient for Ezrin exhibit defective endo-lysosomal pathway, attributable to the compromised EGFR/AKT signaling, ultimately leading to retinal degeneration. Our data identify a pivotal mechanism of endo-lysosomal signaling involving Ezrin and its associated EGFR/TSC complex, which are essential for retinal function.

    1. Cell Biology

    Beta Cells: Opportunity makes a hub or a leader

    Marjan Slak Rupnik
    Insight

    Functional subpopulations of β-cells emerge to control pulsative insulin secretion in the pancreatic islets of mice through calcium oscillations.

    1. Cell Biology

    Glucokinase activity controls peripherally located subpopulations of β-cells that lead islet Ca2+ oscillations

    Erli Jin, Jennifer K Briggs ... Matthew J Merrins
    Research Article

    Oscillations in insulin secretion, driven by islet Ca2+ waves, are crucial for glycemic control. Prior studies, performed with single-plane imaging, suggest that subpopulations of electrically coupled β-cells have privileged roles in leading and coordinating the propagation of Ca2+ waves. Here, we used three-dimensional (3D) light-sheet imaging to analyze the location and Ca2+ activity of single β-cells within the entire islet at >2 Hz. In contrast with single-plane studies, 3D network analysis indicates that the most highly synchronized β-cells are located at the islet center, and remain regionally but not cellularly stable between oscillations. This subpopulation, which includes ‘hub cells’, is insensitive to changes in fuel metabolism induced by glucokinase and pyruvate kinase activation. β-Cells that initiate the Ca2+ wave (leaders) are located at the islet periphery, and strikingly, change their identity over time via rotations in the wave axis. Glucokinase activation, which increased oscillation period, reinforced leader cells and stabilized the wave axis. Pyruvate kinase activation, despite increasing oscillation frequency, had no effect on leader cells, indicating the wave origin is patterned by fuel input. These findings emphasize the stochastic nature of the β-cell subpopulations that control Ca2+ oscillations and identify a role for glucokinase in spatially patterning ‘leader’ β-cells.