Evaluating phase separation in live cells: diagnosis, caveats, and functional consequences
Evaluating phase separation in live cells: diagnosis, caveats, and functional consequences
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DOI：
10.1101/gad.331520.119
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发表时间：
2019-12-01
影响因子：
10.5
通讯作者：
Tjian, Robert
中科院分区：
文献类型：
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作者：
McSwiggen, David T.;Mir, Mustafa;Tjian, Robert
液-液相分离(LLP)可能是复杂细胞环境中分子自组织的一般机制，这一想法在细胞生物界引起了极大的兴奋和热情。虽然这一概念并不新鲜，但它的卓越地位重新引起了人们对塑造和驱动从基因表达到细胞分裂再到应激反应的各种细胞自组装过程的机制的兴趣。在体外，生化数据有助于得出生物分子可以相分离的一些基本原理和分子语法，以及这些相互作用的分子基础。对于同样的原理是否适用于活细胞内的生理环境，目前还缺乏确凿的证据。在这个视角下，我们分析了支持体内跨多个细胞过程的相分离的证据。我们发现，体内LLP的证据通常是现象学的，不足以区分相分离和其他可能的机制。此外，LLP在体内的因果关系和功能后果更加难以捉摸。我们强调了对处于内源状态和生理丰度的蛋白质进行定量测量的重要性，并对可能产生更具决定性结果的实验提出了建议。
The idea that liquid-liquid phase separation (LLPS) may be a general mechanism by which molecules in the complex cellular milieu may self-organize has generated much excitement and fervor in the cell biology community. While this concept is not new, its rise to preeminence has resulted in renewed interest in the mechanisms that shape and drive diverse cellular self-assembly processes from gene expression to cell division to stress responses. In vitro biochemical data have been instrumental in deriving some of the fundamental principles and molecular grammar by which biological molecules may phase separate, and the molecular basis of these interactions. Definitive evidence is lacking as to whether the same principles apply in the physiological environment inside living cells. In this Perspective, we analyze the evidence supporting phase separation in vivo across multiple cellular processes. We find that the evidence for in vivo LLPS is often phenomenological and inadequate to discriminate between phase separation and other possible mechanisms. Moreover, the causal relationship and functional consequences of LLPS in vivo are even more elusive. We underscore the importance of performing quantitative measurements on proteins in their endogenous state and physiological abundance, as well as make recommendations for experiments that may yield more conclusive results.