Correlation of actin crosslinker and capper expression levels with stereocilia growth phases

Matthew R. Avenarius, Katherine W. Saylor, Megan R. Lundeberg, Phillip Wilmarth, Jung Bum Shin, Kateri J. Spinelli, James M. Pagana, Leonardo Andrade, Bechara Kachar, Dongseok Choi, Larry David, Peter Barr-Gillespie

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

During development of the chick cochlea, actin crosslinkers and barbed-end cappers presumably influence growth and remodeling of the actin paracrystal of hair cell stereocilia. We used mass spectrometry to identify and quantify major actin-associated proteins of the cochlear sensory epithelium from E14 to E21, when stereocilia widen and lengthen. Tight actin crosslinkers (i.e. fascins, plastins, and espin) are expressed dynamically during cochlear epithelium development between E7 and E21, with FSCN2 replacing FSCN1 and plastins remaining low in abundance. Capping protein, a barbed-end actin capper, is located at stereocilia tips; it is abundant during growth phase II, when stereocilia have ceased elongating and are increasing in diameter. Capping protein levels then decline during growth phase III, when stereocilia reinitiate barbed-end elongation. Although actin crosslinkers are readily detected by electron microscopy in developing chick cochlea stereocilia, quantitative mass spectrometry of stereocilia isolated from E21 chick cochlea indicated that tight crosslinkers are present there in stoichiometric ratios relative to actin that are much lower than their ratios for vestibular stereocilia. These results demonstrate the value of quantitation of global protein expression in chick cochlea during stereocilia development.

Original languageEnglish (US)
Pages (from-to)606-620
Number of pages15
JournalMolecular and Cellular Proteomics
Volume13
Issue number2
DOIs
Publication statusPublished - Feb 2014

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Analytical Chemistry

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