Agrobacterium tumefaciens divisome proteins regulate the transition from polar growth to cell division
Agrobacterium tumefaciens divisome proteins regulate the transition from polar growth to cell division
复制标题
DOI：
10.1111/mmi.14212
复制
发表时间：
2019-04-01
影响因子：
3.6
通讯作者：
Brown, Pamela J. B.
中科院分区：
文献类型：
--
作者：
Howell, Matthew;Aliashkevich, Alena;Brown, Pamela J. B.
在极区生长的α变形菌中，在细胞分裂过程中限制肽聚糖生物合成到极区并将肽聚糖生物合成重新定向到细胞中间的机制在很大程度上是未知的。在这里，我们探讨了农杆菌的早期分裂蛋白，包括三种FtsZ同源物，FtsA和FtsW在从极性生长到细胞中期生长和最终细胞分裂的转变中的作用。虽然三个FtsZ同源物中有两个定位于细胞中期，表现出GTPase活性并形成共聚物，但只有一个FtsZ（AT）是细胞分裂所必需的。我们发现FtsZ（AT）不仅是收缩和细胞分离所必需的，而且也是细胞中期肽聚糖合成的起始和极性肽聚糖生物合成的停止所必需的。在a . tummefaciens中，FtsZ（AT）的耗竭导致了一个惊人的表型：细胞广泛分支，并通过尖端分裂事件积累生长活性极点。当细胞分裂在后期由于FtsA或FtsW的耗尽而受阻时，极性生长终止，中细胞出现异位生长极点。综上所述，本研究表明，产瘤内生芽孢杆菌FtsZ对细胞极性生长和细胞分裂的调控有明显的贡献。
The mechanisms that restrict peptidoglycan biosynthesis to the pole during elongation and re-direct peptidoglycan biosynthesis to mid-cell during cell division in polar-growing Alphaproteobacteria are largely unknown. Here, we explore the role of early division proteins of Agrobacterium tumefaciens including three FtsZ homologs, FtsA and FtsW in the transition from polar growth to mid-cell growth and ultimately cell division. Although two of the three FtsZ homologs localize to mid-cell, exhibit GTPase activity and form co-polymers, only one, FtsZ(AT), is required for cell division. We find that FtsZ(AT) is required not only for constriction and cell separation, but also for initiation of peptidoglycan synthesis at mid-cell and cessation of polar peptidoglycan biosynthesis. Depletion of FtsZ(AT) in A. tumefaciens causes a striking phenotype: cells are extensively branched and accumulate growth active poles through tip splitting events. When cell division is blocked at a later stage by depletion of FtsA or FtsW, polar growth is terminated and ectopic growth poles emerge from mid-cell. Overall, this work suggests that A. tumefaciens FtsZ makes distinct contributions to the regulation of polar growth and cell division.