A moving ParA gradient on the nucleoid directs subcellular cargo transport via a chemophoresis force.
A moving ParA gradient on the nucleoid directs subcellular cargo transport via a chemophoresis force.
复制标题
DOI：
10.4161/19490992.2014.987581
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Mizuuchi K
中科院分区：
文献类型：
--
作者：
Vecchiarelli AG;Seol Y;Neuman KC;Mizuuchi K
DNA分离是所有生命的关键过程，尽管对真核生物有丝分裂有相对较好的理解，但细菌中的机制仍不清楚。细菌细胞的小尺寸和其亚细胞组织中涉及的因子的数量使得难以在体内受控条件下研究单个系统。我们开发了一种无细胞技术来重建和可视化细菌ParA介导的分离系统。我们的研究为不使用经典的细胞骨架丝或马达蛋白的运输模式提供了直接证据。相反，我们证明，ParA型DNA分离系统可以建立一个传播的帕拉ATP酶梯度的类核表面上，产生所需的力的空间限制的货物，如质粒或大的细胞器的定向运动，并分配多个货物等距离的细胞内。在这里，我们提出的关键原则，我们的扩散棘轮模型的帕拉介导的运输和扩大数学推导的化学电泳力使用实验确定的生化和细胞参数。
DNA segregation is a critical process for all life, and although there is a relatively good understanding of eukaryotic mitosis, the mechanism in bacteria remains unclear. The small size of a bacterial cell and the number of factors involved in its subcellular organization make it difficult to study individual systems under controlled conditions in vivo. We developed a cell-free technique to reconstitute and visualize bacterial ParA-mediated segregation systems. Our studies provide direct evidence for a mode of transport that does not use a classical cytoskeletal filament or motor protein. Instead, we demonstrate that ParA-type DNA segregation systems can establish a propagating ParA ATPase gradient on the nucleoid surface, which generates the force required for the directed movement of spatially confined cargoes, such as plasmids or large organelles, and distributes multiple cargos equidistant to each other inside cells. Here we present the critical principles of our diffusion-ratchet model of ParA-mediated transport and expand on the mathematically derived chemophoresis force using experimentally-determined biochemical and cellular parameters.