Cell membranes in bacteria are laterally polarized to produce specific environments for membrane proteins, e.g., proteins involved in cell division which accumulate at mid-cell or the cell poles. An interesting result of such membrane-lipid interplay is the reorganization of lipid domains together with membrane-bound proteins at the onset of cell division, suggesting functional significance of membrane compartments in the cell cycle. Here, by adopting the key bacterial division proteins MinC, MinD, MinE, FtsA and FtsZ as an archetypal spatial patterning system, we present a simple vesicle-based in vitro model to explore the mutual dependence of protein pattern formation and membrane heterogeneity. Like many other peripheral membrane proteins, Min proteins exhibit preferential binding and macro-scale pattern formation at Ld domains, which leads to altered oscillation mode selection in phase-separated membrane compartments (GUVs). Moreover, incorporating bacterial division proteins within phase-separated GUVs leads to blebbing-like membrane deformations followed by the reorganization of Lo domains aligning at the neck region of the bleb, which agrees well with the domain rearrangement in bacterial membranes immediately preceding the radial constriction process. Overall, the presented in vitro model system showcases a basic framework to better comprehend the cellular division mechanism in consideration of complex cellular lipid environments.

中文翻译：

---

合成细胞模型中膜相分离与细菌分裂蛋白质动力学之间的相互依赖性


细菌中的细胞膜横向极化，为膜蛋白产生特定的环境，例如，参与细胞分裂的蛋白质，这些蛋白质在细胞中段或细胞极积累。这种膜-脂质相互作用的一个有趣结果是脂质结构域与膜结合蛋白在细胞分裂开始时的重组，这表明膜区室在细胞周期中的功能意义。在这里，通过采用关键的细菌分裂蛋白 MinC、MinD、MinE、FtsA 和 FtsZ 作为原型空间模式系统，我们提出了一个简单的基于囊泡的体外模型，以探索蛋白质模式形成和膜异质性的相互依赖性。与许多其他外周膜蛋白一样，Min 蛋白在 Ld 结构域表现出优先结合和宏观模式形成，这导致相分离膜区室 （GUV） 中振荡模式的选择发生变化。此外，在相分离的 GUV 中掺入细菌分裂蛋白会导致类似气泡的膜变形，然后 Lo 结构域的重组在 Bleb 的颈部区域对齐，这与径向收缩过程之前细菌膜中的结构域重排非常吻合。总体而言，所提出的体外模型系统展示了一个基本框架，可以更好地理解考虑到复杂的细胞脂质环境的细胞分裂机制。