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Mechanical stability of αT-catenin and its activation by force for vinculin binding

αT (Testes)-catenin, a critical factor regulating cell–cell adhesion in the heart, directly couples the cadherin-catenin complex to the actin cytoskeleton at the intercalated disk (ICD), a unique cell–cell junction that couples cardiomyocytes. Loss of αT-catenin in mice reduces plakophilin2 and conn...

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Autores principales: Pang, Si Ming, Le, Shimin, Kwiatkowski, Adam V., Yan, Jie
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6727763/
https://www.ncbi.nlm.nih.gov/pubmed/31318313
http://dx.doi.org/10.1091/mbc.E19-02-0102
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author Pang, Si Ming
Le, Shimin
Kwiatkowski, Adam V.
Yan, Jie
author_facet Pang, Si Ming
Le, Shimin
Kwiatkowski, Adam V.
Yan, Jie
author_sort Pang, Si Ming
collection PubMed
description αT (Testes)-catenin, a critical factor regulating cell–cell adhesion in the heart, directly couples the cadherin-catenin complex to the actin cytoskeleton at the intercalated disk (ICD), a unique cell–cell junction that couples cardiomyocytes. Loss of αT-catenin in mice reduces plakophilin2 and connexin 43 recruitment to the ICD. Since αT-catenin is subjected to mechanical stretch during actomyosin contraction in cardiomyocytes, its activity could be regulated by mechanical force. To provide insight in how force regulates αT-catenin function, we investigated the mechanical stability of the putative, force-sensing middle (M) domain of αT-catenin and determined how force impacts vinculin binding to αT-catenin. We show that 1) physiological levels of force, <15 pN, are sufficient to unfold the three M domains; 2) the M1 domain that harbors the vinculin-binding site is unfolded at ∼6 pN; and 3) unfolding of the M1 domain is necessary for high-affinity vinculin binding. In addition, we quantified the binding kinetics and affinity of vinculin to the mechanically exposed binding site in M1 and observed that αT-catenin binds vinculin with low nanomolar affinity. These results provide important new insights into the mechanosensing properties of αT-catenin and how αT-catenin regulates cell–cell adhesion at the cardiomyocyte ICD.
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spelling pubmed-67277632019-10-07 Mechanical stability of αT-catenin and its activation by force for vinculin binding Pang, Si Ming Le, Shimin Kwiatkowski, Adam V. Yan, Jie Mol Biol Cell Articles αT (Testes)-catenin, a critical factor regulating cell–cell adhesion in the heart, directly couples the cadherin-catenin complex to the actin cytoskeleton at the intercalated disk (ICD), a unique cell–cell junction that couples cardiomyocytes. Loss of αT-catenin in mice reduces plakophilin2 and connexin 43 recruitment to the ICD. Since αT-catenin is subjected to mechanical stretch during actomyosin contraction in cardiomyocytes, its activity could be regulated by mechanical force. To provide insight in how force regulates αT-catenin function, we investigated the mechanical stability of the putative, force-sensing middle (M) domain of αT-catenin and determined how force impacts vinculin binding to αT-catenin. We show that 1) physiological levels of force, <15 pN, are sufficient to unfold the three M domains; 2) the M1 domain that harbors the vinculin-binding site is unfolded at ∼6 pN; and 3) unfolding of the M1 domain is necessary for high-affinity vinculin binding. In addition, we quantified the binding kinetics and affinity of vinculin to the mechanically exposed binding site in M1 and observed that αT-catenin binds vinculin with low nanomolar affinity. These results provide important new insights into the mechanosensing properties of αT-catenin and how αT-catenin regulates cell–cell adhesion at the cardiomyocyte ICD. The American Society for Cell Biology 2019-07-22 /pmc/articles/PMC6727763/ /pubmed/31318313 http://dx.doi.org/10.1091/mbc.E19-02-0102 Text en © 2019 Pang, Le, et al. “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society for Cell Biology. http://creativecommons.org/licenses/by-nc-sa/3.0 This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License.
spellingShingle Articles
Pang, Si Ming
Le, Shimin
Kwiatkowski, Adam V.
Yan, Jie
Mechanical stability of αT-catenin and its activation by force for vinculin binding
title Mechanical stability of αT-catenin and its activation by force for vinculin binding
title_full Mechanical stability of αT-catenin and its activation by force for vinculin binding
title_fullStr Mechanical stability of αT-catenin and its activation by force for vinculin binding
title_full_unstemmed Mechanical stability of αT-catenin and its activation by force for vinculin binding
title_short Mechanical stability of αT-catenin and its activation by force for vinculin binding
title_sort mechanical stability of αt-catenin and its activation by force for vinculin binding
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6727763/
https://www.ncbi.nlm.nih.gov/pubmed/31318313
http://dx.doi.org/10.1091/mbc.E19-02-0102
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