Department of Oral and Maxillofacial Surgery/Central Laboratory, School and Hospital of Stomatology , Peking University, National Engineering Laboratory for Digital and Material Technology of Stomatology , 22 Zhonguancun South Road , Haidian District, Beijing 100081 , China.
State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , 5 Yiheyuan Road , Beijing 100871 , China.
ACS Nano. 2018 Jun 26;12(6):6137-6146. doi: 10.1021/acsnano.8b02469. Epub 2018 Jun 12.
Bacterial binary cell division requires accurate placement of division machinery. FtsZ, a vital component of the division machinery, can assemble into filaments and self-organize into a ring structure (Z ring) at the appropriate site for cell division. MapZ, a recently identified FtsZ regulator in Streptococcaceae, has been found to localize at the midcell where it helps to properly position the FtsZ ring. However, its mechanism is still unclear. Here, by using total internal reflection fluorescence microscopy, super-resolution imaging, and single molecule tracking, we investigated the mechanism by which MapZ controls the position of the FtsZ ring. Our results show that FtsZ exhibits a dynamic treadmilling motion in S. mutans. Importantly, depletion of MapZ leads to the unconstrained movement of treadmilling FtsZ filaments and a shorter lifetime of the constricting FtsZ ring, which is frequently misplaced. Furthermore, by revealing that MapZ forms an immobile ring-like nanostructure at the division site, our study suggests that MapZ forms a stable ring that acts as a nanotrack to guide and restrict treadmilling FtsZ filaments in S. mutans.
细菌的二元细胞分裂需要精确放置分裂机制。FtsZ 是分裂机制的重要组成部分，它可以组装成纤维，并在适当的分裂部位自组织成环结构（Z 环）。MapZ 是最近在链球菌科中发现的一种 FtsZ 调节因子，已被发现定位于细胞中部，有助于正确定位 FtsZ 环。然而，其机制尚不清楚。在这里，我们通过使用全内反射荧光显微镜、超分辨率成像和单分子跟踪技术，研究了 MapZ 控制 FtsZ 环位置的机制。我们的结果表明，FtsZ 在变形链球菌中表现出动态的踏车运动。重要的是，MapZ 的耗竭导致踏车运动的 FtsZ 纤维不受约束的运动，以及限制 FtsZ 环的寿命缩短，这经常导致其位置错误。此外，通过揭示 MapZ 在分裂部位形成不可移动的环状纳米结构，我们的研究表明，MapZ 形成一个稳定的环，作为纳米轨道来引导和限制变形链球菌中的踏车运动的 FtsZ 纤维。
