Institute for Systems Genetics, New York University Langone Medical Center, 435 E 30th Street, New York, NY 10010, USA.
German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Göttingen, Germany.
Mol Cell. 2022 Oct 6;82(19):3693-3711.e10. doi: 10.1016/j.molcel.2022.08.016. Epub 2022 Sep 14.
Phase separation can concentrate biomolecules and accelerate reactions. However, the mechanisms and principles connecting this mesoscale organization to signaling dynamics are difficult to dissect because of the pleiotropic effects associated with disrupting endogenous condensates. To address this limitation, we engineered new phosphorylation reactions within synthetic condensates. We generally found increased activity and broadened kinase specificity. Phosphorylation dynamics within condensates were rapid and could drive cell-cycle-dependent localization changes. High client concentration within condensates was important but not the main factor for efficient phosphorylation. Rather, the availability of many excess client-binding sites together with a flexible scaffold was crucial. Phosphorylation within condensates was also modulated by changes in macromolecular crowding. Finally, the phosphorylation of the Alzheimer's-disease-associated protein Tau by cyclin-dependent kinase 2 was accelerated within condensates. Thus, condensates enable new signaling connections and can create sensors that respond to the biophysical properties of the cytoplasm.
相分离可以浓缩生物分子并加速反应。然而，由于破坏内源性凝聚物会产生多效性影响，因此将这种介观组织与信号转导动力学联系起来的机制和原理很难剖析。为了解决这个限制，我们在合成凝聚物中设计了新的磷酸化反应。我们普遍发现活性增加和激酶特异性拓宽。凝聚物内的磷酸化动力学很快，可以驱动细胞周期依赖性定位变化。凝聚物内的高客户浓度很重要，但不是高效磷酸化的主要因素。相反，许多多余的客户结合位点的可用性以及灵活的支架至关重要。凝聚物内的磷酸化也受到大分子拥挤变化的调节。最后，凝聚物内的 CDK2 对阿尔茨海默病相关蛋白 Tau 的磷酸化加速。因此，凝聚物可以实现新的信号连接，并可以创建对细胞质的生物物理特性做出响应的传感器。
