University of Virginia, Charlottesville, VA, USA.
University of Texas Health Science Center at Houston, Houston, TX, USA.
Nat Chem Biol. 2020 Dec;16(12):1321-1330. doi: 10.1038/s41589-020-00688-0. Epub 2020 Nov 16.
Maintenance of lipid asymmetry across the two leaflets of the plasma membrane (PM) bilayer is a ubiquitous feature of eukaryotic cells. Loss of this asymmetry has been widely associated with cell death. However, increasing evidence points to the physiological importance of non-apoptotic, transient changes in PM asymmetry. Such transient scrambling events are associated with a range of biological functions, including intercellular communication and intracellular signaling. Thus, regulation of interleaflet lipid distribution in the PM is a broadly important but underappreciated cellular process with key physiological and structural consequences. Here, we compile the mounting evidence revealing multifaceted, functional roles of PM asymmetry and transient loss thereof. We discuss the consequences of reversible asymmetry on PM structure, biophysical properties and interleaflet coupling. We argue that despite widespread recognition of broad aspects of membrane asymmetry, its importance in cell biology demands more in-depth investigation of its features, regulation, and physiological and pathological implications.
维持质膜（PM）双层的两个叶层之间的脂质不对称性是真核细胞的普遍特征。这种不对称性的丧失与细胞死亡广泛相关。然而，越来越多的证据表明 PM 不对称性的非凋亡、短暂变化具有生理重要性。这种短暂的混乱事件与一系列生物学功能有关，包括细胞间通讯和细胞内信号转导。因此，PM 中隔层脂质分布的调节是一个广泛但被低估的具有关键生理和结构后果的重要细胞过程。在这里，我们汇集了越来越多的证据，揭示了 PM 不对称性及其短暂丧失的多方面功能作用。我们讨论了可逆不对称性对 PM 结构、生物物理特性和隔层耦合的影响。我们认为，尽管广泛认识到膜不对称性的广泛方面，但它在细胞生物学中的重要性需要更深入地研究其特征、调节及其生理和病理意义。
