Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
Department of Physics, National University of Singapore, Singapore 117542, Singapore.
Sci Adv. 2019 Dec 18;5(12):eaav2720. doi: 10.1126/sciadv.aav2720. eCollection 2019 Dec.
The vinculin-mediated mechanosensing requires establishment of stable mechanical linkages between vinculin to integrin at focal adhesions and to cadherins at adherens junctions through associations with the respective adaptor proteins talin and α-catenin. However, the mechanical stability of these critical vinculin linkages has yet to be determined. Here, we developed a single-molecule detector assay to provide direct quantification of the mechanical lifetime of vinculin association with the vinculin binding sites in both talin and α-catenin, which reveals a surprisingly high mechanical stability of the vinculin-talin and vinculin-α-catenin interfaces that have a lifetime of >1000 s at forces up to 10 pN and can last for seconds to tens of seconds at 15 to 25 pN. Our results suggest that these force-bearing intermolecular interfaces provide sufficient mechanical stability to support the vinculin-mediated mechanotransduction at cell-matrix and cell-cell adhesions.
黏连蛋白介导的机械感知需要通过与衔接蛋白 talin 和 α-连环蛋白的结合，在黏着斑处将黏连蛋白与整合素建立稳定的机械连接，并在黏着连接处将黏连蛋白与钙黏蛋白建立稳定的机械连接。然而，这些关键黏连蛋白连接的机械稳定性尚未确定。在这里，我们开发了一种单分子检测分析方法，以直接定量黏连蛋白与 talin 和 α-连环蛋白中黏连蛋白结合位点的结合的机械寿命，这揭示了黏连蛋白与 talin 和黏连蛋白与 α-连环蛋白的界面具有令人惊讶的高机械稳定性，其在高达 10 pN 的力下的寿命> 1000 s，并且在 15 至 25 pN 下可以持续数秒至数十秒。我们的结果表明，这些承载力的分子间界面提供了足够的机械稳定性，以支持细胞-基质和细胞-细胞黏附中黏连蛋白介导的机械转导。
