Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction

Abstract Calcium- and integrin-binding protein 2 (CIB2) plays a crucial role in mechanoelectrical transduction (MET) in cochlear hair cells, particularly in modulating the function and localization of the core components of MET channels TMC1/2. CIB2, along with its homolog CIB3, interacts with TMC1/...

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Main Authors: Yahong Li, Jiasheng Chen, Wenli Jiang, Jin Ye, Xuan Zhang, Chao Wang
Format: Article
Language:English
Published: Nature Portfolio 2025-02-01
Series:Communications Biology
Online Access:https://doi.org/10.1038/s42003-025-07761-1
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author Yahong Li
Jiasheng Chen
Wenli Jiang
Jin Ye
Xuan Zhang
Chao Wang
author_facet Yahong Li
Jiasheng Chen
Wenli Jiang
Jin Ye
Xuan Zhang
Chao Wang
author_sort Yahong Li
collection DOAJ
description Abstract Calcium- and integrin-binding protein 2 (CIB2) plays a crucial role in mechanoelectrical transduction (MET) in cochlear hair cells, particularly in modulating the function and localization of the core components of MET channels TMC1/2. CIB2, along with its homolog CIB3, interacts with TMC1/2 through two distinct sites. Here, our study unveils CIB2/3’s role as a calcium sensor in its interaction with TMC1. Utilizing X-ray crystallography, we elucidate the high-resolution structure of the mammalian CIB2-TMC1 complex. Structural analyses reveal that cation-bound CIB2 forms a negatively charged surface that aligns with a positively charged surface on the TMC1 N-terminus. Moreover, our data suggest that Ca²⁺ modulates CIB2’s interaction with both the N-terminal domain and the loop 1 region of TMC1, and that Ca²⁺-bound CIB2 is capable of simultaneously binding to both regions of TMC1. Critically, we examine pathogenic variants of CIB2 associated with hearing loss, discovering that these variants have differential impacts on CIB2’s interactions with TMC1’s dual binding sites, displaying diminished calcium-binding affinities for several of these CIB2 mutations. These findings provide a deeper understanding of the molecular mechanisms underlying CIB2 function and its implications in hearing loss, offering potential avenues for therapeutic interventions in deafness.
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spelling doaj-art-2560cf0a5b104d70ac79cdf84597ecdb2025-08-20T03:03:40ZengNature PortfolioCommunications Biology2399-36422025-02-018111210.1038/s42003-025-07761-1Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransductionYahong Li0Jiasheng Chen1Wenli Jiang2Jin Ye3Xuan Zhang4Chao Wang5Department of Neurology, the First Affiliated Hospital of USTC, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Hefei National Research Center for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of ChinaDepartment of Neurology, the First Affiliated Hospital of USTC, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Hefei National Research Center for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of ChinaDepartment of Neurology, the First Affiliated Hospital of USTC, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Hefei National Research Center for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of ChinaDepartment of Neurology, the First Affiliated Hospital of USTC, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Hefei National Research Center for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of ChinaMinistry of Education Key Laboratory for Membrane-less Organelles and Cellular Dynamics, Biomedical Sciences and Health Laboratory of Anhui Province, University of Science and Technology of ChinaDepartment of Neurology, the First Affiliated Hospital of USTC, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Hefei National Research Center for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of ChinaAbstract Calcium- and integrin-binding protein 2 (CIB2) plays a crucial role in mechanoelectrical transduction (MET) in cochlear hair cells, particularly in modulating the function and localization of the core components of MET channels TMC1/2. CIB2, along with its homolog CIB3, interacts with TMC1/2 through two distinct sites. Here, our study unveils CIB2/3’s role as a calcium sensor in its interaction with TMC1. Utilizing X-ray crystallography, we elucidate the high-resolution structure of the mammalian CIB2-TMC1 complex. Structural analyses reveal that cation-bound CIB2 forms a negatively charged surface that aligns with a positively charged surface on the TMC1 N-terminus. Moreover, our data suggest that Ca²⁺ modulates CIB2’s interaction with both the N-terminal domain and the loop 1 region of TMC1, and that Ca²⁺-bound CIB2 is capable of simultaneously binding to both regions of TMC1. Critically, we examine pathogenic variants of CIB2 associated with hearing loss, discovering that these variants have differential impacts on CIB2’s interactions with TMC1’s dual binding sites, displaying diminished calcium-binding affinities for several of these CIB2 mutations. These findings provide a deeper understanding of the molecular mechanisms underlying CIB2 function and its implications in hearing loss, offering potential avenues for therapeutic interventions in deafness.https://doi.org/10.1038/s42003-025-07761-1
spellingShingle Yahong Li
Jiasheng Chen
Wenli Jiang
Jin Ye
Xuan Zhang
Chao Wang
Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction
Communications Biology
title Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction
title_full Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction
title_fullStr Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction
title_full_unstemmed Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction
title_short Structural insights into calcium-dependent CIB2-TMC1 interaction in hair cell mechanotransduction
title_sort structural insights into calcium dependent cib2 tmc1 interaction in hair cell mechanotransduction
url https://doi.org/10.1038/s42003-025-07761-1
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