Influence of FtsZ GTPase activity and concentration on nanoscale Z-ring structure in vivo revealed by three-dimensional Superresolution imaging.
Influence of FtsZ GTPase activity and concentration on nanoscale Z-ring structure in vivo revealed by three-dimensional Superresolution imaging.
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DOI：
10.1002/bip.22895
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发表时间：
2016-10
期刊：
影响因子：
2.9
通讯作者：
Xiao J
中科院分区：
文献类型：
--
作者：
Lyu Z;Coltharp C;Yang X;Xiao J
FtsZ是一种必需的细菌细胞骨架蛋白，在中间细胞组装成环状结构（Z环）以进行胞质分裂。在体外，FtsZ表现出多态性聚合成不同形式的细丝的基础上，其GTdR活性，浓度和缓冲条件。在体内，Z-环似乎是点状的和不均匀的组织，虽然连续的，均匀的Z-环结构也已观察到。了解Z环在体内是如何组织的是很重要的，因为它为Z环在胞质分裂中的功能作用提供了结构基础。在这里，我们使用三维（3D）超分辨率显微镜评估的影响，GTdR的活性和FtsZ浓度的Z-环在体内的组织。我们发现，Z-环变得更加同质时，组装在一个GTP酶缺陷突变体的存在下，无论是野生型或突变FtsZ过表达。这些结果表明，Z-环的体内组织在很大程度上取决于FtsZ的固有聚合性质，这是显着影响的GTdR活性和浓度的FtsZ。我们的工作提供了一个统一的主题，以协调以前的观察不同的Z-环结构，并支持一个模型，其中的WT Z-环包括松散关联的，异质分布的FtsZ集群。
FtsZ is an essential bacterial cytoskeletal protein that assembles into a ring-like structure (Z-ring) at midcell to carry out cytokinesis. In vitro, FtsZ exhibits polymorphism in polymerizing into different forms of filaments based on its GTPase activity, concentration, and buffer condition. In vivo, the Z-ring appeared to be punctate and heterogeneously organized, although continuous, homogenous Z-ring structures have also been observed. Understanding how the Z-ring is organized in vivo is important because it provides a structural basis for the functional role of the Z-ring in cytokinesis. Here, we assess the effects of both GTPase activity and FtsZ concentration on the organization of the Z-ring in vivo using three-dimensional (3D) superresolution microscopy. We found that the Z-ring became more homogenous when assembled in the presence of a GTPase-deficient mutant, and upon overexpression of either wt or mutant FtsZ. These results suggest that the in vivo organization of the Z-ring is largely dependent on the intrinsic polymerization properties of FtsZ, which are significantly influenced by the GTPase activity and concentration of FtsZ. Our work provides a unifying theme to reconcile previous observations of different Z-ring structures, and supports a model in which the wt Z-ring comprises loosely associated, heterogeneously distributed FtsZ clusters.