A multi-step nucleation process determines the kinetics of prion-like domain phase separation.
A multi-step nucleation process determines the kinetics of prion-like domain phase separation.
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DOI：
10.1038/s41467-021-24727-z
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发表时间：
2021-07-23
影响因子：
16.6
通讯作者：
Mittag T
中科院分区：
文献类型：
--
作者：
Martin EW;Harmon TS;Hopkins JB;Chakravarthy S;Incicco JJ;Schuck P;Soranno A;Mittag T
通过液-液相分离（LLPS）的区室化已经成为生物分子在空间和时间中组织的普遍机制。在这里，我们结合联合收割机快速混合时间分辨小角X射线散射（SAXS）的方法来表征组装动力学的一个原型朊病毒样域的平衡技术，其相边界和大小分布的集群相分离之前的特征。我们发现两个动力学制度上的微到毫秒的时间尺度，区分集群的大小分布。在纳米级，小复合物以低亲和力形成。在初始的不利复合物组装之后，以更高的亲和力添加另外的单体。在中尺度下，组装类似于经典的均匀成核。仔细的多管齐下的表征是必要的冷凝物组装机制的理解，并将促进了解生物相分离的动力学是如何在生物分子中编码。生物蛋白质相分离的成核机理知之甚少。在这里，作者用hnRNPA1的低复杂度域（LCD）进行了时间分辨的SAXS实验，并在微米到毫秒的时间尺度上揭示了多种动力学机制。最初，单个蛋白质崩溃。然后通过蛋白质簇大小分布区分的两个步骤发生成核。
Compartmentalization by liquid-liquid phase separation (LLPS) has emerged as a ubiquitous mechanism underlying the organization of biomolecules in space and time. Here, we combine rapid-mixing time-resolved small-angle X-ray scattering (SAXS) approaches to characterize the assembly kinetics of a prototypical prion-like domain with equilibrium techniques that characterize its phase boundaries and the size distribution of clusters prior to phase separation. We find two kinetic regimes on the micro- to millisecond timescale that are distinguished by the size distribution of clusters. At the nanoscale, small complexes are formed with low affinity. After initial unfavorable complex assembly, additional monomers are added with higher affinity. At the mesoscale, assembly resembles classical homogeneous nucleation. Careful multi-pronged characterization is required for the understanding of condensate assembly mechanisms and will promote understanding of how the kinetics of biological phase separation is encoded in biomolecules. The nucleation mechanisms of biological protein phase separation are poorly understood. Here, the authors perform time-resolved SAXS experiments with the low-complexity domain (LCD) of hnRNPA1 and uncover multiple kinetic regimes on the micro- to millisecond timescale. Initially, individual proteins collapse. Nucleation then occurs via two steps distinguished by their protein cluster size distributions.
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影响因子：
16.6
作者：
Ambadipudi S;Biernat J;Riedel D;Mandelkow E;Zweckstetter M
通讯作者：
Zweckstetter M
影响因子：
16.6
作者：
de Sancho, David;Sirur, Anshul;Best, Robert B.
通讯作者：
Best, Robert B.
影响因子：
5.5
作者：
Kalkowski, Joseph;Liu, Chang;Liu, Ying
通讯作者：
Liu, Ying
影响因子：
64.5
作者：
Feric M;Vaidya N;Harmon TS;Mitrea DM;Zhu L;Richardson TM;Kriwacki RW;Pappu RV;Brangwynne CP
通讯作者：
Brangwynne CP
影响因子：
19
作者：
Boeynaems S;Alberti S;Fawzi NL;Mittag T;Polymenidou M;Rousseau F;Schymkowitz J;Shorter J;Wolozin B;Van Den Bosch L;Tompa P;Fuxreiter M
通讯作者：
Fuxreiter M