Stereocilia-staircase spacing is influenced by myosin III motors and their cargos espin-1 and espin-like

Authors

• Seham Ebrahim, National Institutes of Health, Bethesda, Maryland
• Matthew R. Avenarius, Oregon Health & Science University, Portland
• M’hamed Grati, National Institutes of Health, Bethesda, Maryland
• Jocelyn F. Krey, Oregon Health & Science University, Portland
• Alanna M. Windsor, National Institutes of Health, Bethesda, Maryland
• Aurea D. Sousa, National Institutes of Health, Bethesda, Maryland
• Angela Ballesteros, National Institutes of Health, Bethesda, Maryland
• Runjia Cui, National Institutes of Health, Bethesda, Maryland
• Bryan A. Millis, National Institutes of Health, Bethesda, Maryland
• Felipe T. Salles, National Institutes of Health, Bethesda, Maryland
• Michelle A. Baird, Florida State University, Tallahassee
• Michael W. Davidson, Florida State University, Tallahassee
• Sherri M. Jones, University of Nebraska-LincolnFollow
• Dongseok Choi, Oregon Health and Science University, PortlandFollow
• Lijin Dong, National Institutes of Health, Bethesda, Maryland
• Manmeet H. Raval, Penn State University College of Medicine
• Christopher M. Yengo, Penn State University College of Medicine
• Peter G. Barr- Gillespie, Oregon Health & Science University, PortlandFollow
• Bechara Kachar, National Institutes of Health, Bethesda, MarylandFollow

Document Type

Article

Date of this Version

2016

Citation

NATURE COMMUNICATIONS | 7:10833 | DOI: 10.1038/ncomms10833

Comments

This work is licensed under a Creative Commons Attribution 4.0 International License

Abstract

Hair cells tightly control the dimensions of their stereocilia, which are actin-rich protrusions with graded heights that mediate mechanotransduction in the inner ear. Two members of the myosin-III family, MYO3A and MYO3B, are thought to regulate stereocilia length by transporting cargos that control actin polymerization at stereocilia tips. We show that eliminating espin-1 (ESPN-1), an isoform of ESPN and a myosin-III cargo, dramatically alters the slope of the stereocilia staircase in a subset of hair cells. Furthermore, we show that espin-like (ESPNL), primarily present in developing stereocilia, is also a myosin-III cargo and is essential for normal hearing. ESPN-1 and ESPNL each bind MYO3A and MYO3B, but differentially influence how the two motors function. Consequently, functional properties of different motor-cargo combinations differentially affect molecular transport and the length of actin protrusions. This mechanism is used by hair cells to establish the required range of stereocilia lengths within a single cell.