Cell-Sized Confinement Initiates Phase Separation of Polymer Blends and Promotes Fractionation upon Competitive Membrane Wetting
Cell-Sized Confinement Initiates Phase Separation of Polymer Blends and Promotes Fractionation upon Competitive Membrane Wetting
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DOI：
10.1021/acsmaterialslett.2c00404
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发表时间：
2022-08
影响因子：
11.4
通讯作者：
Chiho Watanabe;T. Furuki;Yuki Kanakubo;Fumiya Kanie;Keisuke Koyanagi;J. Takeshita;M. Yanagisawa
中科院分区：
文献类型：
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作者：
Chiho Watanabe;T. Furuki;Yuki Kanakubo;Fumiya Kanie;Keisuke Koyanagi;J. Takeshita;M. Yanagisawa
由液-液相分离(LLP)驱动的生物分子凝聚物作为一种新型的生物体活性调节剂受到了广泛的关注。在细胞内LLP中，一个重要的问题是什么类型的生物分子在什么条件下形成凝聚体。最近，有报道称，LLP凝聚体在润湿时可以调节膜结构。然而，另一种相反的可能性，即膜润湿是否调节LLP，仍未被探索。使用不同大小的短聚乙二醇(PEG)和长葡聚糖共混物包裹在脂膜中，我们证明了膜润湿调节细胞大小空间中的LLP并改变平衡状态。在小液滴中，两相区域扩展到本体之外，分馏程度随着液滴尺寸的减小而增加。我们解释了空间大小依赖的LLP是因为短的聚乙二醇比葡聚糖具有更高的润湿性。这表明细胞大小的限制可以在不同分子之间竞争膜润湿性时调节LLP，从而使LLPS原理在活细胞中是可行的。
Biomolecular condensates driven by liquid–liquid phase separation (LLPS) have received attention as novel activity regulators of living organisms. In intracellular LLPS, an important question is what type of biomolecules form condensates under what conditions. Recently, LLPS condensates have been reported to regulate the membrane structure upon wetting. However, the opposite possibility, i.e., whether membrane wetting regulates the LLPS, remains unexplored. Using variously sized droplets of short polyethylene glycol (PEG) and long dextran blends encapsulated with a lipid membrane, we demonstrate that membrane wetting regulates LLPS in cell-sized spaces and alters the equilibrium state. In small droplets, the two-phase region expands beyond the bulk, and the degree of fractionation increases as the droplet size decreases. We explain the space-size-dependent LLPS from the higher wettability of short PEG than dextran. This shows that cell-sized confinement can regulate LLPS upon competition for membrane wettability among various molecules, rendering this LLPS principle feasible in living cells.