Dynamic force sensing of filamin revealed in single-molecule experiments
Dynamic force sensing of filamin revealed in single-molecule experiments
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DOI：
10.1073/pnas.1211274109
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发表时间：
2012-11-27
影响因子：
11.1
通讯作者：
Rief, Matthias
中科院分区：
文献类型：
--
作者：
Rognoni, Lorenz;Stigler, Johannes;Rief, Matthias
机械力是细胞反应和发育的重要信号，但力感知的详细分子机制在很大程度上还没有被探索。细胞骨架蛋白丝素是连接细胞骨架和跨膜复合体的关键元件，如整合素或von Willebrand受体糖蛋白Ib。在这里，我们使用单分子机械测量表明，最近报道的人丝蛋白A的Ig结构域对20-21起到了自抑制力可激活机械传感器的作用。我们开发了一种机械单分子竞争分析方法，允许在线观察目标多肽在溶液中与应变结构域对的结合事件。我们发现，丝氨酸力感知是一个发生在快速平衡中的高度动态的过程，在2到5个pN之间，它与目标多肽的亲和力增加了17倍。我们发现的平衡机制可以为细胞力传感提供一个通用的方案。
Mechanical forces are important signals for cell response and development, but detailed molecular mechanisms of force sensing are largely unexplored. The cytoskeletal protein filamin is a key connecting element between the cytoskeleton and transmembrane complexes such as integrins or the von Willebrand receptor glycoprotein Ib. Here, we show using single-molecule mechanical measurements that the recently reported Ig domain pair 20-21 of human filamin A acts as an autoinhibited force-activatable mechanosensor. We developed a mechanical single-molecule competition assay that allows online observation of binding events of target peptides in solution to the strained domain pair. We find that filamin force sensing is a highly dynamic process occurring in rapid equilibrium that increases the affinity to the target peptides by up to a factor of 17 between 2 and 5 pN. The equilibrium mechanism we find here can offer a general scheme for cellular force sensing.