Liquid-liquid phase separation is a key organizational principle in eukaryotic cells, on par with intracellular membranes. It allows cells to concentrate specific proteins into condensates, increasing reaction rates and achieving switch-like regulation. We propose two active mechanisms that can explain how cells regulate condensate formation and size. In both, the cell regulates the activity of an enzyme, often a kinase, that adds post-translational modifications to condensate proteins. In enrichment inhibition, the enzyme enriches in the condensate and weakens interactions, as seen in stress granules (SGs), Cajal bodies, and P granules. In localization-induction, condensates form around immobilized enzymes that strengthen interactions, as observed in DNA repair, transmembrane signaling, and microtubule assembly. These models can guide studies into the many emerging roles of biomolecular condensates.

中文翻译：

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主动调节生物分子冷凝物的机制。

液-液相分离是真核细胞中与细胞内膜同等的关键组织原理。它可以使细胞将特定的蛋白质浓缩成冷凝液，从而提高反应速度并实现类似开关的调节。我们提出了两种活跃的机制，可以解释细胞如何调节冷凝物的形成和大小。在这两种细胞中，细胞都调节一种酶（通常是一种激酶）的活性，该酶将翻译后修饰添加到缩合蛋白上。在富集抑制中，如在应力颗粒（SGs​​），Cajal体和P颗粒中所见，酶在冷凝物中富集并减弱了相互作用。在定位诱导中，在DNA修复，跨膜信号传导和微管组装中观察到，固定化酶周围会形成冷凝物，从而增强相互作用。