Inner ear hair cells detect sound through deflection of stereocilia, the microvilli-like projections that are arranged in rows of graded heights. Calcium and integrin-binding protein 2 is essential for hearing and localizes to stereocilia, but its exact function is unknown. Here, we have characterized two mutant mouse lines, one lacking calcium and integrin-binding protein 2 and one carrying a human deafness-related Cib2 mutation, and show that both are deaf and exhibit no mechanotransduction in auditory hair cells, despite the presence of tip links that gate the mechanotransducer channels. In addition, mechanotransducing shorter row stereocilia overgrow in hair cell bundles of both Cib2 mutants. Furthermore, we report that calcium and integrin-binding protein 2 binds to the components of the hair cell mechanotransduction complex, TMC1 and TMC2, and these interactions are disrupted by deafness-causing Cib2 mutations. We conclude that calcium and integrin-binding protein 2 is required for normal operation of the mechanotransducer channels and is involved in limiting the growth of transducing stereocilia.

Document Type


Publication Date


Notes/Citation Information

Published in Nature Communications, v. 8, article no. 43, p. 1-13.

© The Author(s) 2017

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Digital Object Identifier (DOI)


Funding Information

This work was supported by the NIDCD/NIH grants R01DC012564 (Z.M.A.), R01DC014658 (G.I.F.), R01DC01362 (R.F.), R01DC011803 (S.R.) and partly by the Medical Research Council, UK grants MC-A022-5PB91 (W.R.S.), and MCU142684175 (S.D.M.B.) and a Wellcome Trust Investigator Award (W.R.S.).

Related Content

Supplementary Information accompanies this paper at doi:10.1038/s41467-017-00061-1.

41467_2017_61_MOESM1_ESM.pdf (58601 kB)
Supplementary Information