PomZ, a ParA-like protein, regulates Z-ring formation and cell division in Myxococcus xanthus
PomZ, a ParA-like protein, regulates Z-ring formation and cell division in Myxococcus xanthus
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DOI：
10.1111/mmi.12094
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发表时间：
2013-01-01
影响因子：
3.6
通讯作者：
Sogaard-Andersen, Lotte
中科院分区：
文献类型：
--
作者：
Treuner-Lange, Anke;Aguiluz, Kryssia;Sogaard-Andersen, Lotte
对分裂部位的准确定位对于产生具有正确染色体数目的适当大小的子细胞至关重要。在细菌中，分裂通常依赖于微管蛋白同系物FtsZ在分裂部位组装成Z-环。在这里，我们发现黄色粘球菌类PomZ蛋白的缺失导致了分裂缺陷，形成了无染色体的微细胞和丝状细胞。缺乏PomZ还导致Z环的形成减少和形成的少数Z环的错误定位。PomZ的定位受细胞周期调控，在染色体分离后、FtsZ之前和FtsZ缺失的情况下，PomZ在中部细胞的分裂部位积累。FtsZ在体外表现出协同的GTP水解，但在体外没有形成可检测到的细丝。在黄花草细胞提取液中，PomZ与FtsZ相互作用。这些数据表明，PomZ对Z环的形成是重要的，并且是Z环形成和细胞分裂的空间调节因子。PomZ在中层细胞的定位依赖于细胞周期，为细胞周期进程和Z环的形成提供了一种耦合机制。此外，数据表明，PomZ是一个系统的一部分，该系统将FtsZ招募到中细胞，从而将Z环的形成限制在这个位置。
Accurate positioning of the division site is essential to generate appropriately sized daughter cells with the correct chromosome number. In bacteria, division generally depends on assembly of the tubulin homologue FtsZ into the Z-ring at the division site. Here, we show that lack of the ParA-like protein PomZ in Myxococcus xanthus resulted in division defects with the formation of chromosome-free minicells and filamentous cells. Lack of PomZ also caused reduced formation of Z-rings and incorrect positioning of the few Z-rings formed. PomZ localization is cell cycle regulated, and PomZ accumulates at the division site at midcell after chromosome segregation but prior to FtsZ as well as in the absence of FtsZ. FtsZ displayed cooperative GTP hydrolysis in vitro but did not form detectable filaments in vitro. PomZ interacted with FtsZ in M. xanthus cell extracts. These data show that PomZ is important for Z-ring formation and is a spatial regulator of Z-ring formation and cell division. The cell cycle-dependent localization of PomZ at midcell provides a mechanism for coupling cell cycle progression and Z-ring formation. Moreover, the data suggest that PomZ is part of a system that recruits FtsZ to midcell, thereby, restricting Z-ring formation to this position.