MinC spatially controls bacterial cytokinesis by antagonizing the scaffolding function of FtsZ
MinC spatially controls bacterial cytokinesis by antagonizing the scaffolding function of FtsZ
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DOI：
10.1016/j.cub.2008.01.042
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发表时间：
2008-02-26
期刊：
影响因子：
9.2
通讯作者：
Lutkenhaus, Joe
中科院分区：
文献类型：
--
作者：
Dajkovic, Alex;Lan, Ganhui;Lutkenhaus, Joe
背景资料：细菌中的胞质分裂由称为Z环的细胞动力学环介导，其形成用于募集其他细胞分裂蛋白的支架。Z环由FtsZ细丝组成，但对它们在Z环中的组织结构知之甚少。在大肠杆菌中，Min系统通过阻止Z环远离中间细胞的组装而有助于胞质分裂的空间调节。效应器的最小系统，MinC，抑制Z环组装的机制是不清楚的。结果：在这里，我们报告说，MinC控制的FtsZ的支架功能，通过拮抗FtsZ结构的机械完整性。具体地，MinC拮抗FtsZ细丝处于固体样凝胶状态的能力。MinC是一种模块化蛋白，其两个结构域（MinC（c）和MinC（N））协同抑制FtsZ功能。MinCc直接与FtsZ聚合物相互作用，将MinC靶向至Z环。MinCc还阻止FtsZ细丝之间的横向相互作用，这种活性在细胞骨架蛋白中似乎是独特的。由于MinCc在体内是抑制性的，这表明FtsZ细丝之间的横向相互作用对于Z环的结构完整性是重要的。MinCN通过削弱长丝中FtsZ分子之间的纵向键，导致聚合物刚性损失和随后的聚合物缩短，从而有助于MinC活性。在我们的研究结果的基础上，我们开发的Z环的第一个计算模型和研究MinC.Conclusions的影响：FtsZ的支架活性的控制可能代表了细菌胞质分裂的一个普遍的调节机制。
Background: Cytokinesis in bacteria is mediated by a cytokinetic ring, termed the Z ring, which forms a scaffold for recruitment of other cell-division proteins. The Z ring is composed of FtsZ filaments, but their organization in the Z ring is poorly understood. In Escherichia coli, the Min system contributes to the spatial regulation of cytokinesis by preventing the assembly of the Z ring away from midcell. The effector of the Min system, MinC, inhibits Z ring assembly by a mechanism that is not clear.Results: Here, we report that MinC controls the scaffolding function of FtsZ by antagonizing the mechanical integrity of FtsZ structures. Specifically, MinC antagonizes the ability of FtsZ filaments to be in a solid-like gel state. MinC is a modular protein whose two domains (MinC(c) and MinC(N)) synergize to inhibit FtsZ function. MinCc interacts directly with FtsZ polymers to target MinC to Z rings. MinCc also prevents lateral interactions between FtsZ filaments, an activity that seems to be unique among cytoskeletal proteins. Because MinCc is inhibitory in vivo, it suggests that lateral interactions between FtsZ filaments are important for the structural integrity of the Z ring. MinCN contributes to MinC activity by weakening the longitudinal bonds between FtsZ molecules in a filament leading to a loss of polymer rigidity and consequent polymer shortening. On the basis of our results, we develop the first computational model of the Z ring and study the effects of MinC.Conclusions: Control over the scaffolding activity of FtsZ probably represents a universal regulatory mechanism of bacterial cytokinesis.