Compact, genetically encoded coiled-coil sensors with tunable pN thresholds and multiple readouts transform in vivo force measurement into a broadly accessible tool, while revealing that clathrin—not just actin—transmits forces during endocytosis.
We described a modular approach to construct mechano-sensors that can be used inside living cells, and validated their performance in different biological systems. Our new design has the potential to democratize in vivo force quantification in every biology lab
Genetically encoded coiled coil mechano-sensors with tunable force thresholds (3-13 pN) and modular readout systems enable comprehensive force measurements across diverse biological systems, revealing that formin Cdc12 experiences 6 pN tension during cytokinesis, epsin Ent1 transmits force primarily through clathrin lattice interactions rather than actin, and vinculin molecules exhibit heterogeneous force distributions with 90% experiencing forces above 5 pN in focal adhesions independent of substrate stiffness.
Mechanical forces are critical for virtually all fundamental biological processes, yet quantification of mechanical forces at the molecular scale in vivo remains challenging. Here, we present a new strategy using calibrated coiled coils as genetically encoded, compact, tunable, and modular mechano-sensors to substantially simplify force measurement in vivo, via diverse readouts (luminescence, fluorescence and analytical biochemistry) and instrumentation readily available in biology labs. We demonstrate the broad applicability and ease-of-use of these coiled coil mechano-sensors by measuring forces during cytokinesis (formin Cdc12) and endocytosis (epsin Ent1) in yeast, force distributions in nematode axons (β-spectrin UNC-70), and forces transmitted to the nucleus (mini-nesprin-2G) and within focal adhesions (vinculin) in mammalian cells. We report discoveries in intracellular force transmission that have been elusive to existing tools.