Abstract
Since the emergence of molecular tension sensors, the understanding of mechanical forces has advanced substantially. However, visualizing molecular tension in mammalian tissues has remained challenging owing to the technical constraints of the Förster resonance energy transfer (FRET)-based molecular tension sensors. Here, we develop a molecular tension sensor based on circularly permuted EGFP with an elastic linker, which is inserted into either αActinin or αCatenin and then fused with mCherry at the C-terminus to simultaneously visualize tension and the amount of sensor protein. This single-fluorophore tension indicator enables subtle tension changes to be visualized simply from color tone under superresolution microscopy. We further generate H11 knock-in mice expressing these indicators, revealing a molecular-specific regulation of mechanical load within tissues. Thus, our molecular tension indicators provide a powerful approach for probing the complex and heterogeneous regulation of mechanical forces in vivo mammalian systems.
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The data supporting the findings of this study are available within the paper and its Supplementary Information. Plasmids generated in this study have been deposited in Addgene under accession codes: 252385 and 252386. Uncropped and unedited images of blots and gels are available in the Supplementary Information. Numerical source data for graphs and charts can be found in Supplementary Data 1. All other data are available from the corresponding author upon reasonable request.
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Acknowledgements
We thank N. Watanabe (Kyoto University, Kyoto, Japan), S.H. Yoshimura (Kyoto University, Kyoto, Japan), Y. Kamioka (Kansai Medical University, Osaka, Japan) and S. Hirano (Kansai Medical University, Osaka, Japan), for insightful discussions, M. Ohkura (Kyushu University of Health and Welfare, Miyazaki, Japan) for providing an expression plasmid of G-CaMP8. This project was supported by grants from Japan Society for the Promotion of Science (16H07353, 17K09586, 20K08502, and 23K07589 to M.H.), TAKEDA Science Foundation, The Novartis Foundation (16-113), SENSHIN Medical Research Foundation to M.H, and the Strategic Project for Proofreading and Submission Support of International Academic Papers by Kansai Medical University to M.H. This research was also supported by Research Support Project for Life Science and Drug Discovery (Basis for Supporting Innovative Drug Discovery and Life Science Research (BINDS)) from AMED under Grant Number JP24ama121020.
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M.H. conceived the study, developed the methodology, and supervised the project. K. Fujiwara, K. Fujiki, and M.H. performed the investigation. K. Fujiki, K.S., I.S., T.N., and M.H. provided resources. M.H. performed formal analysis and visualization, and wrote, edited, and finalized the manuscript. T.O.A. and T.N. contributed to the writing (review and editing).
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Fujiwara, K., Fujiki, K., Akama, T.O. et al. Molecular tension indicators reveal unexpectedly complex regulation of tension in live mouse organs. Commun Biol (2026). https://doi.org/10.1038/s42003-026-09746-0
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DOI: https://doi.org/10.1038/s42003-026-09746-0
