Department of Physics and Astronomy, Institute for the Physics of Living Systems University College London, London WC1E 6BT, United Kingdom.
MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom.
Phys Rev Lett. 2020 Jan 31;124(4):048102. doi: 10.1103/PhysRevLett.124.048102.
Experiments have suggested that bacterial mechanosensitive channels separate into 2D clusters, the role of which is unclear. By developing a coarse-grained computer model we find that clustering promotes the channel closure, which is highly dependent on the channel concentration and membrane stress. This behaviour yields a tightly regulated gating system, whereby at high tensions channels gate individually, and at lower tensions the channels spontaneously aggregate and inactivate. We implement this positive feedback into the model for cell volume regulation, and find that the channel clustering protects the cell against excessive loss of cytoplasmic content.
实验表明,细菌机械敏感通道会分离成 2D 簇,但其作用尚不清楚。通过开发一个粗粒度的计算机模型,我们发现聚类促进了通道关闭,这高度依赖于通道浓度和膜应力。这种行为产生了一个严格调节的门控系统,即在高张力下通道单独门控,而在较低的张力下通道自发聚集并失活。我们将这种正反馈机制引入到细胞体积调节的模型中,发现通道聚类可以保护细胞免受细胞质内容物过度损失的影响。