Pressure and Osmolyte Effects on Liquid-Liquid Phase Separation Phenomena and Condensates of Proteins

近年来，液液相分离(LLP)现象被认为在生物分子凝聚体的形成过程中起着重要的作用。利用UV/Vis、CD、FTIR光谱、相差光和荧光显微镜技术，我们计划研究温度、压力和天然渗透剂对不同类型凝聚体LLP现象的联合影响，主要集中在Kbar-区压力的影响。我们小组的第一次研究表明，相当出人意料的是，蛋白质的液-液相变是自然界中发现的最敏感的压力过程之一。因此，在深海高压条件下茁壮成长的生物，遇到的压力高达1千巴制度，必须应对生物分子凝析油的这种高度压力敏感性，可能使用特定的渗透分子。然后，我们将仔细研究在极端环境条件下这种无膜室在调节多肽和核酸的分配、构象动力学、自组装和活性方面的有效性。由于生命可能起源于深海，这一知识还将阐明利用LLP进行生物功能可能的进化优势，并为在面对外部压力时支持细胞进化的自组织原理提供见解。

In recent years, liquid-liquid phase separation (LLPS) phenomena have been recognized to play an important role in the membrane-less compartmentalization of cells through the formation of biomolecular condensates. Using UV/Vis, CD, FTIR spectroscopies, phase-contrast light and fluorescence microscopy techniques, we plan to study the combined effects of temperature, pressure and natural osmolytes on LLPS phenomena of different types of such condensates, focusing essentially on the effect of pressure up to the kbar-regime. First studies of our group have shown, quite unexpectedly, that liquid-liquid phase transitions of proteins are among the most pressure sensitive processes found in Nature. Hence, organisms thriving at high-pressure conditions in the deep sea, where pressures up to 1 kbar regime are encountered, have to cope with this high pressure-sensitivity of biomolecular condensates, probably utilizing particular osmolytes. We will then scrutinize the effectiveness of such membrane-less compartments under extreme environmental conditions in modulating the partitioning, conformational dynamics, self-assembly, and activity of peptides and nucleic acids. As life probably started in the deep sea, this knowledge will also shed light on the possible evolutionary advantages of utilizing LLPS for biological function and provide insights into the self-organization principles underpinning cellular evolution in the face of external stresses.