PDF(Pubmed)
Abstract：
Cellular membranes exhibit a multitude of highly curved morphologies such as buds, nanotubes, cisterna-like sheets defining the outlines of organelles. Here, we mimic cell compartmentation using an aqueous two-phase system of dextran and poly(ethylene glycol) encapsulated in giant vesicles. Upon osmotic deflation, the vesicle membrane forms nanotubes, which undergo surprising morphological transformations at the liquid-liquid interfaces inside the vesicles. At these interfaces, the nanotubes transform into cisterna-like double-membrane sheets (DMS) connected to the mother vesicle via short membrane necks. Using super-resolution (stimulated emission depletion) microscopy and theoretical considerations, we construct a morphology diagram predicting the tube-to-sheet transformation, which is driven by a decrease in the free energy. Nanotube knots can prohibit the tube-to-sheet transformation by blocking water influx into the tubes. Because both nanotubes and DMSs are frequently formed by cellular membranes, understanding the formation and transformation between these membrane morphologies provides insight into the origin and evolution of cellular organelles.
摘要：
细胞膜表现出许多高度弯曲的形态，例如芽，纳米管,定义细胞器轮廓的池状薄片。这里,我们使用包裹在巨大囊泡中的葡聚糖和聚（乙二醇）的双水相系统模拟细胞分隔。在渗透放气时，囊泡膜形成纳米管，在囊泡内部的液-液界面发生令人惊讶的形态转变。在这些接口上，纳米管转化为通过短膜颈与母囊泡连接的类似水箱的双膜片（DMS）。使用超分辨率（受激发射损耗）显微镜和理论考虑，我们构建了一个形态学图，预测管到板的转变，这是由自由能的减少驱动的。纳米管结可以通过阻止水流入管中而阻止管到板的转变。因为纳米管和DMS通常都是由细胞膜形成的，了解这些膜形态之间的形成和转化，可以深入了解细胞器的起源和进化。
