The perception of sound and balance depends on the mechanosensory function of the hair bundle, a group of actin-filled stereocilia that project from the apical surface of auditory and vestibular hair cells. The study of deafness-linked genes has led to the identification of a number of proteins that are localized to the hair bundle and contribute to its development and function [1]. Despite these advances, the complete network of proteins that constitute the hair bundle and regulate its maturation, maintenance and function remain poorly defined. Although the mechanisms by which proteins are specifically transported to the bundle are also poorly understood, accumulated evidence suggests that myosin motor proteins may play important roles [2]. The goal of this proposal is to identify the bundle proteins that are transported to and maintained within the hair bundle during its formation and to test the hypothesis that myosin-VIIa (MYO7A) plays a role in the transport of these proteins. Using proteomics approaches as well as other biochemical techniques, the aims in this proposal will 1) identify in an unbiased manner the protein networks that are enriched within the hair bundle during and after bundle assembly, 2) determine whether MYO7A plays a role in the transport of specific proteins to the bundle and 3) identify which of these bundle-specific proteins directly or indirectly interact with MYO7A. The results of these studies will significantly contribute to our molecular understanding of bundle assembly and function and could help guide the development of therapeutic strategies for hair cell repair and regeneration.

Public Health Relevance

The studies in this proposal will lead to a more comprehensive understanding of the molecular mechanisms underlying the development and function of auditory and vestibular hair cells. The proposed research will also help determine how deafness-causing mutations in specific genes perturb the assembly and function of the sensory apparatus within the hair cell. The results from these studies may guide the future identification of new deafness genes that will aid in improving the diagnosis and treatments of various hearing and balance disorders.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Postdoctoral Individual National Research Service Award (F32)
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Communication Disorders Review Committee (CDRC)
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Sklare, Dan
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Oregon Health and Science University
Schools of Medicine
United States
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Krey, Jocelyn F; Drummond, Meghan; Foster, Sarah et al. (2016) Annexin A5 is the Most Abundant Membrane-Associated Protein in Stereocilia but is Dispensable for Hair-Bundle Development and Function. Sci Rep 6:27221
Wilmarth, Phillip A; Krey, Jocelyn F; Shin, Jung-Bum et al. (2015) Hair-bundle proteomes of avian and mammalian inner-ear utricles. Sci Data 2:150074
Krey, Jocelyn F; Sherman, Nicholas E; Jeffery, Erin D et al. (2015) The proteome of mouse vestibular hair bundles over development. Sci Data 2:150047
Krey, Jocelyn F; Wilmarth, Phillip A; Shin, Jung-Bum et al. (2014) Accurate label-free protein quantitation with high- and low-resolution mass spectrometers. J Proteome Res 13:1034-44
Shin, Jung-Bum; Krey, Jocelyn F; Hassan, Ahmed et al. (2013) Molecular architecture of the chick vestibular hair bundle. Nat Neurosci 16:365-74