Sarmento Maria J, Hof Martin, Šachl Radek
J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova, Prague, Czechia.
Front Cell Dev Biol. 2020 Apr 28;8:284. doi: 10.3389/fcell.2020.00284. eCollection 2020.
The plasma membrane is a complex system, consisting of two layers of lipids and proteins compartmentalized into small structures called nanodomains. Despite the asymmetric composition of both leaflets, coupling between the layers is surprisingly strong. This can be evidenced, for example, by recent experimental studies performed on phospholipid giant unilamellar vesicles showing that nanodomains formed in the outer layer are perfectly registered with those in the inner leaflet. Similarly, microscopic phase separation in one leaflet can induce phase separation in the opposing leaflet that would otherwise be homogeneous. In this review, we summarize the current theoretical and experimental knowledge that led to the current view that domains are - irrespective of their size - commonly registered across the bilayer. Mechanisms inducing registration of nanodomains suggested by theory and calculations are discussed. Furthermore, domain coupling is evidenced by experimental studies based on the sparse number of methods that can resolve registered from independent nanodomains. Finally, implications that those findings using model membrane studies might have for cellular membranes are discussed.
质膜是一个复杂的系统，由两层脂质和蛋白质组成，这些成分被分隔成称为纳米结构域的小结构。尽管两个小叶的组成不对称，但两层之间的耦合却出奇地强。例如，最近对磷脂巨型单层囊泡进行的实验研究可以证明这一点，这些研究表明在外层形成的纳米结构域与内层的纳米结构域完美对齐。同样，一个小叶中的微观相分离可以诱导相对小叶中的相分离，否则该小叶将是均匀的。在这篇综述中，我们总结了当前的理论和实验知识，这些知识导致了目前的观点，即无论结构域大小如何，它们通常在整个双层中都是对齐的。我们讨论了理论和计算提出的诱导纳米结构域对齐的机制。此外，基于能够区分对齐的纳米结构域和独立的纳米结构域的少量方法所进行的实验研究也证明了结构域耦合。最后，我们讨论了使用模型膜研究的这些发现可能对细胞膜产生的影响。
