title: Molecular architecture of the chick vestibular hair bundle.
abstract: Hair bundles of the inner ear have a specialized structure and protein composition that underlies their sensitivity to mechanical stimulation. Using mass spectrometry, we identified and quantified >1,100 proteins, present from a few to 400,000 copies per stereocilium, from purified chick bundles; 336 of these were significantly enriched in bundles. Bundle proteins that we detected have been shown to regulate cytoskeleton structure and dynamics, energy metabolism, phospholipid synthesis and cell signaling. Three-dimensional imaging using electron tomography allowed us to count the number of actin-actin cross-linkers and actin-membrane connectors; these values compared well to those obtained from mass spectrometry. Network analysis revealed several hub proteins, including RDX (radixin) and SLC9A3R2 (NHERF2), which interact with many bundle proteins and may perform functions essential for bundle structure and function. The quantitative mass spectrometry of bundle proteins reported here establishes a framework for future characterization of dynamic processes that shape bundle structure and function.
authors: Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA.
authors: Jung-Bum
authors: JB
authors: Shin
authors: Jocelyn F
authors: JF
authors: Krey
authors: Ahmed
authors: A
authors: Hassan
authors: Zoltan
authors: Z
authors: Metlagel
authors: Andrew N
authors: AN
authors: Tauscher
authors: James M
authors: JM
authors: Pagana
authors: Nicholas E
authors: NE
authors: Sherman
authors: Erin D
authors: ED
authors: Jeffery
authors: Kateri J
authors: KJ
authors: Spinelli
authors: Hongyu
authors: H
authors: Zhao
authors: Phillip A
authors: PA
authors: Wilmarth
authors: Dongseok
authors: D
authors: Choi
authors: Larry L
authors: LL
authors: David
authors: Manfred
authors: M
authors: Auer
authors: Peter G
authors: PG
authors: Barr-Gillespie
mesh_terms: D000818:Animals; D002642:Chick Embryo; D007758:Ear, Inner / Q000196:embryology / Q000378:metabolism*; D006198:Hair Cells, Auditory / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods*; D059547:Stereocilia / Q000378:metabolism; D014722:Vestibule, Labyrinth / Q000196:embryology / Q000378:metabolism