Bouffanais Roland, Sun Jianmin, Yue Dick K P
Singapore University of Technology and Design, 20 Dover Drive, Singapore 138682.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 May;87(5):052716. doi: 10.1103/PhysRevE.87.052716. Epub 2013 May 29.
Many eukaryotic cells are able to perform directional mechanosensing by directly measuring minute spatial differences in the mechanical stress on their membranes. Here, we explore the limits of a single mechanosensitive channel activation using a two-state double-well model for the gating mechanism. We then focus on the physical limits of directional mechanosensing by a single cell having multiple mechanosensors and subjected to a shear flow inducing a nonuniform membrane tension. Our results demonstrate that the accuracy in sensing the mechanostimulus direction not only increases with cell size and exposure to a signal, but also grows for cells with a near-critical membrane prestress. Finally, the existence of a nonlinear threshold effect, fundamentally limiting the cell's ability to effectively perform directional mechanosensing at a low signal-to-noise ratio, is uncovered.
许多真核细胞能够通过直接测量其膜上机械应力的微小空间差异来进行定向机械传感。在这里，我们使用门控机制的两态双阱模型来探索单个机械敏感通道激活的极限。然后，我们关注具有多个机械传感器并受到诱导不均匀膜张力的剪切流作用的单个细胞进行定向机械传感的物理极限。我们的结果表明，感知机械刺激方向的准确性不仅随着细胞大小和信号暴露而增加，而且对于具有接近临界膜预应力的细胞也会提高。最后，我们发现了一种非线性阈值效应的存在，从根本上限制了细胞在低信噪比下有效进行定向机械传感的能力。
