1. Cell Biology
  2. Neuroscience

The 133-kDa N-terminal domain enables myosin 15 to maintain mechanotransducing stereocilia and is essential for hearing

  1. Qing Fang
  2. Artur A Indzhykulian
  3. Mirna Mustapha
  4. Gavin P Riordan
  5. David F Dolan
  6. Thomas B Friedman
  7. Inna A Belyantseva
  8. Gregory I Frolenkov
  9. Sally A Camper
  10. Jonathan E Bird  Is a corresponding author
  1. University of Michigan, United States
  2. Harvard Medical School, United States
  3. Stanford University, United States
  4. National Institute on Deafness and Other Communication Disorders, United States
  5. University of Michigan Medical School, United States
  6. University of Kentucky, United States
https://doi.org/10.7554/eLife.08627
Share this article
Cite this article
  1. Qing Fang
  2. Artur A Indzhykulian
  3. Mirna Mustapha
  4. Gavin P Riordan
  5. David F Dolan
  6. Thomas B Friedman
  7. Inna A Belyantseva
  8. Gregory I Frolenkov
  9. Sally A Camper
  10. Jonathan E Bird
(2015)
The 133-kDa N-terminal domain enables myosin 15 to maintain mechanotransducing stereocilia and is essential for hearing
eLife 4:e08627.
https://doi.org/10.7554/eLife.08627
  2. Download BibTeX
  3. Download .RIS

Abstract

The precise assembly of inner ear hair cell stereocilia into rows of increasing height is critical for mechanotransduction and the sense of hearing. Yet, how the lengths of actin-based stereocilia are regulated remains poorly understood. Mutations of the molecular motor myosin-15 stunt stereocilia growth and cause deafness. We found that hair cells express two isoforms of myosin-15 through alternative splicing of an N-terminal domain, and that these isoforms selectively traffic to different stereocilia rows. Using an isoform-specific knockout mouse, hair cells expressing only the small isoform remarkably develop normal stereocilia bundles. However, a critical subset of stereocilia with active mechanotransducer channels subsequently retracts. The larger isoform with the N-terminal domain traffics to these specialized stereocilia and prevents disassembly of their actin core. Our results show that myosin-15 isoforms can navigate between functionally distinct classes of stereocilia, and are independently required to assemble and then maintain the intricate hair bundle architecture.

Article and author information

Author details

  1. Qing Fang

    Department of Human Genetics, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.

  2. Artur A Indzhykulian

    Department of Neurobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Mirna Mustapha

    Department of Otolaryngology - Head and Neck Surgery, Stanford University, Stanford, United States
    Competing interests
    The authors declare that no competing interests exist.

  4. Gavin P Riordan

    Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Bethesda, United States
    Competing interests
    The authors declare that no competing interests exist.

  5. David F Dolan

    Department of Otolaryngology, University of Michigan Medical School, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.

  6. Thomas B Friedman

    Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Bethesda, United States
    Competing interests
    The authors declare that no competing interests exist.

  7. Inna A Belyantseva

    Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Bethesda, United States
    Competing interests
    The authors declare that no competing interests exist.

  8. Gregory I Frolenkov

    Department of Physiology, University of Kentucky, Lexington, United States
    Competing interests
    The authors declare that no competing interests exist.

  9. Sally A Camper

    Department of Human Genetics, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.

  10. Jonathan E Bird

    Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Bethesda, United States
    For correspondence
    jonathan.bird@nih.gov
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Jeremy Nathans, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, United States

Ethics

Animal experimentation: All animal procedures were approved by the institutional animal care and use committees (IACUC) at the University of Michigan (#PRO00004639, #PRO00005913, #PRO00005128), the University of Kentucky (#903M2005) and at the NIDCD (#1263-12).

Version history

  1. Received: May 9, 2015
  2. Accepted: August 22, 2015
  3. Accepted Manuscript published: August 24, 2015 (version 1)
  4. Version of Record published: October 6, 2015 (version 2)

Copyright

This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Metrics

  • 3,496
    views
  • 658
    downloads
  • 66
    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. Qing Fang
  2. Artur A Indzhykulian
  3. Mirna Mustapha
  4. Gavin P Riordan
  5. David F Dolan
  6. Thomas B Friedman
  7. Inna A Belyantseva
  8. Gregory I Frolenkov
  9. Sally A Camper
  10. Jonathan E Bird
(2015)
The 133-kDa N-terminal domain enables myosin 15 to maintain mechanotransducing stereocilia and is essential for hearing
eLife 4:e08627.
https://doi.org/10.7554/eLife.08627

Share this article

https://doi.org/10.7554/eLife.08627

Categories and tags

Research organism

Further reading

    1. Cell Biology
    2. Neuroscience

    Hearing: It takes two

    Teresa Nicolson
    Insight

    Two forms of an unconventional myosin motor protein have separate functions in the growth and maintenance of hair bundles in auditory hair cells.

    1. Cancer Biology
    2. Cell Biology

    A syngeneic spontaneous zebrafish model of tp53-deficient, EGFRvIII, and PI3KCAH1047R-driven glioblastoma reveals inhibitory roles for inflammation during tumor initiation and relapse in vivo

    Alex Weiss, Cassandra D'Amata ... Madeline N Hayes
    Research Article

    High-throughput vertebrate animal model systems for the study of patient-specific biology and new therapeutic approaches for aggressive brain tumors are currently lacking, and new approaches are urgently needed. Therefore, to build a patient-relevant in vivo model of human glioblastoma, we expressed common oncogenic variants including activated human EGFRvIII and PI3KCAH1047R under the control of the radial glial-specific promoter her4.1 in syngeneic tp53 loss-of-function mutant zebrafish. Robust tumor formation was observed prior to 45 days of life, and tumors had a gene expression signature similar to human glioblastoma of the mesenchymal subtype, with a strong inflammatory component. Within early stage tumor lesions, and in an in vivo and endogenous tumor microenvironment, we visualized infiltration of phagocytic cells, as well as internalization of tumor cells by mpeg1.1:EGFP+ microglia/macrophages, suggesting negative regulatory pressure by pro-inflammatory cell types on tumor growth at early stages of glioblastoma initiation. Furthermore, CRISPR/Cas9-mediated gene targeting of master inflammatory transcription factors irf7 or irf8 led to increased tumor formation in the primary context, while suppression of phagocyte activity led to enhanced tumor cell engraftment following transplantation into otherwise immune-competent zebrafish hosts. Altogether, we developed a genetically relevant model of aggressive human glioblastoma and harnessed the unique advantages of zebrafish including live imaging, high-throughput genetic and chemical manipulations to highlight important tumor-suppressive roles for the innate immune system on glioblastoma initiation, with important future opportunities for therapeutic discovery and optimizations.

    1. Cancer Biology
    2. Cell Biology

    Cancer: Modeling glioblastoma

    Ian Lorimer
    Insight

    Establishing a zebrafish model of a deadly type of brain tumor highlights the role of the immune system in the early stages of the disease.