Activity-Driven Phase Transition Causes Coherent Flows of Chromatin
Activity-Driven Phase Transition Causes Coherent Flows of Chromatin
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活动驱动的相变导致染色质的相干流动
DOI：
10.1103/physrevlett.131.048401
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发表时间：
2023
影响因子：
8.6
通讯作者：
Grosberg, Alexander Y.
中科院分区：
文献类型：
--
作者：
Eshghi, Iraj;Zidovska, Alexandra;Grosberg, Alexander Y.
我们在染色质动力学模型中发现了一种新型的非平衡相变，它解释了实验中观察到的相干运动。连贯运动是由于与染色质相连的分子马达的长程合作造成的。如果每个马达同时作用于聚合物和周围溶剂，对它们施加相等且相反的力，就会发生协作。这会驱动溶剂流过聚合物，进而影响附近电机的方向，如果驱动足够强，电机的活性极性（“铁磁”）相就会自发形成。根据边界条件，横向流动或持续纵向振荡和波浪都是可能的。预测的长度尺度与实验一致。我们现在掌握了染色质动力学的粗粒度描述，它再现了实验中看到的染色质定向相干流。这种场论描述可以与核环境的其他特征进行分析耦合，例如波动或多孔边界、染色质分布的局部异质性或其活性，从而深入了解活性对细胞核及其内容物的影响。
We discover a new type of nonequilibrium phase transition in a model of chromatin dynamics, which accounts for the coherent motions that have been observed in experiment. The coherent motion is due to the long-range cooperation of molecular motors tethered to chromatin. Cooperation occurs if each motor acts simultaneously on the polymer and the surrounding solvent, exerting on them equal and opposite forces. This drives the flow of solvent past the polymer, which in turn affects the orientation of nearby motors and, if the drive is strong enough, an active polar (“ferromagnetic”) phase of motors can spontaneously form. Depending on boundary conditions, either transverse flows or sustained longitudinal oscillations and waves are possible. Predicted length scales are consistent with experiments. We now have in hand a coarse-grained description of chromatin dynamics which reproduces the directed coherent flows of chromatin seen in experiments. This field-theoretic description can be analytically coupled to other features of the nuclear environment such as fluctuating or porous boundaries, local heterogeneities in the distribution of chromatin or its activity, leading to insights on the effects of activity on the cell nucleus and its contents.