标题： 极性化学感受器通过二聚体三聚体的耦合聚集 显示英文标题

标题： Polar Chemoreceptor Clustering by Coupled Trimers of Dimers

摘要： 细菌趋化受体在细胞极部形成簇，这些簇作为“天线”来放大配体浓度的微小变化。有趣的是，化学受体在多个长度尺度上形成簇。在最小的尺度上，受体形成二聚体，这些二聚体组装成稳定的二聚体阵列。在较大的尺度上，三聚体形成由数千个受体组成的大型极性簇。尽管关于受体簇产生的信号特性已有大量了解，但受体如何定位在细胞极部以及决定簇大小的因素仍不清楚。在这里，我们提出一个基于耦合二聚体三聚体的极性受体簇模型，其中簇的大小被确定为簇-膜自由能的最小值。这种能量包括簇-膜弹性能量的贡献，由于其高固有曲率而惩罚大簇，以及受体-受体耦合促进大簇。我们发现，在弯曲的细胞极部，减少的簇-膜曲率不匹配导致了与实验观察一致的大而稳健的极性簇，而侧向簇则被有效抑制。 显示英文摘要

摘要： Receptors of bacterial chemotaxis form clusters at the cell poles, where clusters act as "antennas" to amplify small changes in ligand concentration. Interestingly, chemoreceptors cluster at multiple length scales. At the smallest scale, receptors form dimers, which assemble into stable timers of dimers. At a large scale, trimers form large polar clusters composed of thousands of receptors. Although much is known about the signaling properties emerging from receptor clusters, it is unknown how receptors localize at the cell poles and what the cluster-size determining factors are. Here, we present a model of polar receptor clustering based on coupled trimers of dimers, where cluster size is determined as a minimum of the cluster-membrane free energy. This energy has contributions from the cluster-membrane elastic energy, penalizing large clusters due to their high intrinsic curvature, and receptor-receptor coupling favoring large clusters. We find that the reduced cluster-membrane curvature mismatch at the curved cell poles leads to large and robust polar clusters in line with experimental observation, while lateral clusters are efficiently suppressed.