Spatially organized molecular interactions are fundamental features underlying many biochemical processes in cells. These spatially defined reactions are essential to ensure high signaling specificity and are indispensable for maintaining cell functions. The construction of synthetic cell models that can resemble such properties is thus important yet less investigated. In this study, we present a reliable method for the rapid production of highly uniform phase-separated liposomes as synthetic cell models. Specifically, a microfluidics-based strategy coupled with custom reagents for generating size-tunable liposomes with various lipid compositions is presented. In addition, an important cell signaling interacting pair, the pleckstrin homology (PH) domain and PIP₂ lipid, is used to demonstrate the controlled molecular assembly inside these liposomes. The result shows that PIP₂ on phase-separated domains successfully recruits the PH domains to realize spatially defined molecular interactions. Such a system is versatile and can be expanded to synthesize other proteins for realizing multiplexed molecular interactions in the same liposome. Phase-separated lipid domains can also be used to recruit targeted proteins to initiate localized reactions, thus paving the way for organizing a complex signaling cascade in the synthetic cell.

中文翻译：

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芯片辅助形成相分离脂质体以重建空间蛋白质-脂质相互作用

空间组织的分子相互作用是细胞中许多生化过程的基本特征。这些空间定义的反应对于确保高信号特异性至关重要，并且对于维持细胞功能是必不可少的。因此，构建与此类特性相似的合成细胞模型很重要，但研究较少。在这项研究中，我们提出了一种可靠的方法，用于快速生产高度均匀的相分离脂质体作为合成细胞模型。具体来说，提出了一种基于微流体的策略，再加上定制试剂，用于生成具有各种脂质成分的尺寸可调脂质体。此外，一个重要的细胞信号相互作用对，pleckstrin 同源性 (PH) 域和 PIP ₂脂质，用于证明这些脂质体内的受控分子组装。结果表明，相分离域上的PIP _{2成功地招募了 PH 域以实现空间定义的分子相互作用。}这样的系统是通用的，可以扩展以合成其他蛋白质，以在同一脂质体中实现多重分子相互作用。相分离的脂质结构域也可用于招募目标蛋白质以启动局部反应，从而为在合成细胞中组织复杂的信号级联铺平道路。