Hair cells, the sensory cells of the inner ear, transduce auditory and vestibular stimuli with their mechanically sensitive hair bundles. Hair bundles contain a small subset of all proteins expressed in hair cells, presumably reflecting bundles' specialized function. Identification of these bundle proteins, difficult because of the small numbers of bundles in any auditory or vestibular organ, will lead to new hypotheses for the assembly, structure, maintenance, and function of hair bundles. Recently, the sensitivity of mass spectrometry methods has increased sufficiently to contemplate large-scale sequencing of the proteins making up the hair bundle (the hair-bundle """"""""proteome""""""""). In our first set of proposed experiments, we will use the isotope-coded affinity tag (ICAT) method to differentially label proteins expressed in hair bundles (comparing to hair- and supporting-cell somas, as a control), then use automated mass-spectrometry methods to identify bundle proteins of high and moderate abundance. In our second set of experiments, we will determine which hair-bundle proteins change in bundle expression when the molecular motor myosin-7a, crucial for human and mouse auditory function, is missing. These experiments will allow us to identify the major proteins of the bundle and allow us to focus on proteins functionally important for bundle function.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21DC006097-02
Application #
6771212
Study Section
Special Emphasis Panel (ZDC1-SRB-A (39))
Program Officer
Freeman, Nancy
Project Start
2003-07-01
Project End
2006-06-30
Budget Start
2004-07-01
Budget End
2006-06-30
Support Year
2
Fiscal Year
2004
Total Cost
$151,000
Indirect Cost
Name
Oregon Health and Science University
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Shin, Jung-Bum; Krey, Jocelyn F; Hassan, Ahmed et al. (2013) Molecular architecture of the chick vestibular hair bundle. Nat Neurosci 16:365-74
Shin, Jung-Bum; Pagana, James; Gillespie, Peter G (2009) Twist-off purification of hair bundles. Methods Mol Biol 493:241-55
Shin, Jung-Bum; Streijger, Femke; Beynon, Andy et al. (2007) Hair bundles are specialized for ATP delivery via creatine kinase. Neuron 53:371-86
Gagnon, Leona H; Longo-Guess, Chantal M; Berryman, Mark et al. (2006) The chloride intracellular channel protein CLIC5 is expressed at high levels in hair cell stereocilia and is essential for normal inner ear function. J Neurosci 26:10188-98