Program in Applied Physics, University of Michigan, Ann Arbor, Michigan 48109, USA; email:
Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Annu Rev Phys Chem. 2021 Apr 20;72:51-72. doi: 10.1146/annurev-physchem-090419-115951. Epub 2020 Dec 1.
Lateral organization in the plane of the plasma membrane is an important driver of biological processes. The past dozen years have seen increasing experimental support for the notion that lipid organization plays an important role in modulating this heterogeneity. Various biophysical mechanisms rooted in the concept of liquid-liquid phase separation have been proposed to explain diverse experimental observations of heterogeneity in model and cell membranes with distinct but overlapping applicability. In this review, we focus on the evidence for and the consequences of the hypothesis that the plasma membrane is poised near an equilibrium miscibility critical point. Critical phenomena explain certain features of the heterogeneity observed in cells and model systems but also go beyond heterogeneity to predict other interesting phenomena, including responses to perturbations in membrane composition.
质膜平面的侧向组织是生物过程的重要驱动因素。在过去的十几年中，越来越多的实验支持这样一种观点，即脂质组织在调节这种异质性方面起着重要作用。各种基于液-液相分离概念的生物物理机制被提出来解释不同模型和细胞膜中异质性的各种实验观察结果，这些机制具有不同但重叠的适用性。在这篇综述中，我们重点关注质膜接近平衡混合临界点的假设的证据及其后果。临界现象解释了细胞和模型系统中观察到的异质性的某些特征，但也超越了异质性，预测了其他有趣的现象，包括对膜成分扰动的响应。
