TY - JOUR
T1 - Heterodimeric capping protein is required for stereocilia length and width regulation
AU - Avenarius, Matthew R.
AU - Krey, Jocelyn F.
AU - Dumont, Rachel A.
AU - Morgan, Clive P.
AU - Benson, Connor B.
AU - Vijayakumar, Sarath
AU - Cunningham, Christopher L.
AU - Scheffer, Deborah I.
AU - Corey, David P.
AU - Müller, Ulrich
AU - Jones, Sherri M.
AU - Barr-Gillespie, Peter G.
N1 - Funding Information:
We thank Ruby Larisch for mouse husbandry, Michael Bateschell for in utero electroporation, Ashok Reddy for assistance in developing DIA methods, Brad Nolen and Connor Balzer for pyrene-labeled actin and mouse capping protein, Chris Yengo for pyrene-labeled actin, Stefan Heller for the anti-TWF2 antibody, Bernd Fritzsch for the Atoh1-Cre mouse line, and John Cooper for helpful discussions and comments on the manuscript. The Capzbtm1a(EUC OMM)Wtsi mouse line, generated by the European Conditional Mouse Mutagenesis Program, was obtained from the European Mouse Mutant Archive. We received support from the following core facilities: mass spectrometry from the University of Virginia W.M. Keck Biomedical Mass Spectrometry Lab and the Oregon Health and Science University (OHSU) Proteomics Shared Resource (partial support from National Institutes of Health core grants P30 EY010572 and P30 CA069533; Orbitrap Fusion S10 OD012246), mouse rederivation from the OHSU Transgenic Mouse Models core, monoclonal antibody purification from the Vaccine and Gene Therapy Institute Monoclonal Antibody Core (OHSU), confocal microscopy from the OHSUAdvanced Light Microscopy Core at The Jungers Center (P30 NS061800 provided support for imaging), and electron microscopy from the Center for Electron Microscopy and Nanofabrication at Portland State University and the OHSU Multiscale Microscopy Core. Technical support was provided by the OHSU-FEI Living Lab and the OHSU Center for Spatial Systems Biomedicine. P.G. Barr-Gillespie was supported by National Institutes of Health grants R01 DC002368, R01 DC011034, and P30 DC005983; P.G. Barr-Gillespie and U. Müller were supported by a National Institutes of Health multi-PI grant (R01 DC014427). D.P. Corey was supported by National Institutes of Health grant R01 DC002281. The authors declare no competing financial interests
Publisher Copyright:
© 2017 Avenarius et al.
PY - 2017/11/1
Y1 - 2017/11/1
N2 - Control of the dimensions of actin-rich processes like filopodia, lamellipodia, microvilli, and stereocilia requires the coordinated activity of many proteins. Each of these actin structures relies on heterodimeric capping protein (CAPZ), which blocks actin polymerization at barbed ends. Because dimension control of the inner ear's stereocilia is particularly precise, we studied the CAP ZB subunit in hair cells. CAP ZB, present at ~100 copies per stereocilium, concentrated at stereocilia tips as hair cell development progressed, similar to the CAP ZB-interacting protein TWF2. We deleted Capzb specifically in hair cells using Atoh1-Cre, which eliminated auditory and vestibular function. Capzb-null stereocilia initially developed normally but later shortened and disappeared; surprisingly, stereocilia width decreased concomitantly with length. CAP ZB2 expressed by in utero electroporation prevented normal elongation of vestibular stereocilia and irregularly widened them. Together, these results suggest that capping protein participates in stereocilia widening by preventing newly elongating actin filaments from depolymerizing.
AB - Control of the dimensions of actin-rich processes like filopodia, lamellipodia, microvilli, and stereocilia requires the coordinated activity of many proteins. Each of these actin structures relies on heterodimeric capping protein (CAPZ), which blocks actin polymerization at barbed ends. Because dimension control of the inner ear's stereocilia is particularly precise, we studied the CAP ZB subunit in hair cells. CAP ZB, present at ~100 copies per stereocilium, concentrated at stereocilia tips as hair cell development progressed, similar to the CAP ZB-interacting protein TWF2. We deleted Capzb specifically in hair cells using Atoh1-Cre, which eliminated auditory and vestibular function. Capzb-null stereocilia initially developed normally but later shortened and disappeared; surprisingly, stereocilia width decreased concomitantly with length. CAP ZB2 expressed by in utero electroporation prevented normal elongation of vestibular stereocilia and irregularly widened them. Together, these results suggest that capping protein participates in stereocilia widening by preventing newly elongating actin filaments from depolymerizing.
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U2 - 10.1083/jcb.201704171
DO - 10.1083/jcb.201704171
M3 - Article
C2 - 28899994
AN - SCOPUS:85032979675
SN - 0021-9525
VL - 216
SP - 3861
EP - 3881
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 11
ER -