Membraneless organelles formed by liquid-liquid phase separation increase bacterial fitness
Membraneless organelles formed by liquid-liquid phase separation increase bacterial fitness
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液-液相分离形成的无膜细胞器提高细菌适应性
DOI：
10.1101/2021.06.24.449778
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Jin X
中科院分区：
文献类型：
--
作者：
Jin X
液-液相分离是细胞基本过程中的一个重要现象。一系列真核系统表现出液体冷凝物。然而，它们在细菌中的功能，一般来说，缺乏膜结合区室，仍然不太清楚。在这里，我们使用高分辨率光学显微镜来观察单个细菌侵袭体，纳米结构的细胞内蛋白质组装体，以掩盖它们在细胞应激中的作用。我们发现，侵略者体内的蛋白质是移动的，并进行动态周转，符合液态。我们的观察结果是在定量协议相分离的液滴形成驱动下的热平衡下，在细胞质中的扩散碰撞后成核的相互作用的蛋白质。我们已经在多种细菌中发现了侵略体，并表明这些新兴的亚稳态液体结构蛋白质组装体通过使细胞能够耐受环境压力来增加细菌的适应性。
Liquid-liquid phase separation is emerging as a crucial phenomenon in several fundamental cell processes. A range of eukaryotic systems exhibit liquid condensates. However, their function in bacteria, which, in general, lack membrane-bound compartments, remains less clear. Here, we used high-resolution optical microscopy to observe single bacterial aggresomes, nanostructured intracellular assemblies of proteins, to undercover their role in cell stress. We find that proteins inside aggresomes are mobile and undergo dynamic turnover, consistent with a liquid state. Our observations are in quantitative agreement with phase-separated liquid droplet formation driven by interacting proteins under thermal equilibrium that nucleate following diffusive collisions in the cytoplasm. We have found aggresomes in multiple species of bacteria and show that these emergent, metastable liquid-structured protein assemblies increase bacterial fitness by enabling cells to tolerate environmental stresses.