Out-of-equilibrium self-assembly of proteins such as actin and tubulin is a key regulatory process controlling cell shape, motion and division. The design of functional nanosystems based on dissipative self-assembly has proven to be remarkably difficult due to a complete lack of control over the spatial and temporal characteristics of the assembly process. Here, we show the dissipative self-assembly of FtsZ protein (a bacterial homologue of tubulin) within coacervate droplets. More specifically, we show how such barrier-free compartments govern the local availability of the energy-rich building block guanosine triphosphate, yielding highly dynamic fibrils. The increased flux of FtsZ monomers at the tips of the fibrils results in localized FtsZ assembly, elongation of the coacervate compartments, followed by division of the fibrils into two. We rationalize the directional growth and division of the fibrils using dissipative reaction–diffusion kinetics and capillary action of the filaments as main inputs. The principle presented here, in which open compartments are used to modulate the rates of dissipative self-assembly by restricting the absorption of energy from the environment, may provide a general route to dissipatively adapting nanosystems exhibiting life-like behaviour.

蛋白质（例如肌动蛋白和微管蛋白）的失衡自组装是控制细胞形状，运动和分裂的关键调控过程。由于完全缺乏对组装过程的时空特性的控制，基于耗散自组装的功能纳米系统的设计已被证明非常困难。在这里，我们显示了凝聚液滴内的FtsZ蛋白（微管蛋白的细菌同源物）的耗散自组装。更具体地说，我们展示了这种无障碍的隔室如何控制能量丰富的构建基三磷酸鸟苷的局部可用性，从而产生高度动态的原纤维。FtsZ单体在原纤维尖端的通量增加导致局部FtsZ组装，凝聚层隔室伸长，然后将原纤维分为两部分。我们使用耗散反应扩散动力学和细丝的毛细作用作为主要输入来合理化原纤维的定向生长和分裂。此处提出的原理（其中使用开放隔室来通过限制环境能量的吸收来调节耗散自组装的速率）可以为耗散地适应表现出生命行为的纳米系统提供一条通用途径。