Positive control of cell division: FtsZ is recruited by SsgB during sporulation of Streptomyces
Positive control of cell division: FtsZ is recruited by SsgB during sporulation of Streptomyces
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DOI：
10.1101/gad.600211
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发表时间：
2011-01-01
影响因子：
10.5
通讯作者：
van Wezel, Gilles P.
中科院分区：
文献类型：
--
作者：
Willemse, Joost;Borst, Jan Willem;van Wezel, Gilles P.
在通过二分裂分裂的细菌中，细胞分裂开始于微管蛋白同系物FtsZ在细胞中期的聚合以形成细胞分裂支架（Z环），随后是其他分裂体组分的募集。目前对细菌细胞分裂控制的观点始于防止不正确的Z环定位的阴性检查点的原理。在这里，我们提供的证据，积极控制孢子形成过程中的链霉菌，通过直接招聘FtsZ的膜相关的分裂体组件SsgB的细胞分裂。体外研究表明，SsgB促进FtsZ的聚合。的相互作用显示在体内的延时成像和福斯特共振能量转移和荧光寿命成像显微镜（FRET FLIM），并通过双杂交研究独立证实。作为确定的荧光恢复后光漂白（FRAP），营业额的FtsZ原丝强烈增加时，Z-环的形成。SsgB对Z环形成的令人惊讶的正控制意味着Z环控制的一种全新方式的进化，这可以通过长多核菌丝中不存在中间细胞参考点来解释。反过来，SsgB的定位是通过正链SsgA介导的，后者的过早表达足以在链霉菌细胞周期的早期阶段直接激活多个Z环的形成和超分裂。
In bacteria that divide by binary fission, cell division starts with the polymerization of the tubulin homolog FtsZ at mid-cell to form a cell division scaffold (the Z ring), followed by recruitment of the other divisome components. The current view of bacterial cell division control starts from the principle of negative checkpoints that prevent incorrect Z-ring positioning. Here we provide evidence of positive control of cell division during sporulation of Streptomyces, via the direct recruitment of FtsZ by the membrane-associated divisome component SsgB. In vitro studies demonstrated that SsgB promotes the polymerization of FtsZ. The interactions are shown in vivo by time-lapse imaging and Forster resonance energy transfer and fluorescence lifetime imaging microscopy (FRET-FLIM), and are corroborated independently via two-hybrid studies. As determined by fluorescence recovery after photobleaching (FRAP), the turnover of FtsZ protofilaments increased strongly at the time of Z-ring formation. The surprising positive control of Z-ring formation by SsgB implies the evolution of an entirely new way of Z-ring control, which may be explained by the absence of a mid-cell reference point in the long multinucleoid hyphae. In turn, the localization of SsgB is mediated through the orthologous SsgA, and premature expression of the latter is sufficient to directly activate multiple Z-ring formation and hyperdivision at early stages of the Streptomyces cell cycle.