Liao Yan, Shinde Vinaya D, Hu Dalong, Xu Zhuang, Söderström Bill, Michie Katharine A, Duggin Iain G
Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW, Australia.
Saw SweeHock School of Public Health, National University of Singapore, Singapore, Singapore.
Nat Commun. 2025 May 31;16(1):5076. doi: 10.1038/s41467-025-60079-8.
Many archaea appear to divide through the coordinated activities of two FtsZ homologues (FtsZ1 and FtsZ2) and another bacterial cell division homologue (SepF), which are part of the midcell division ring. Here, we identify an additional protein (HVO_0739, renamed CdpA) that is involved in cell division in Haloferax volcanii, with homologues in other Haloarchaea. CdpA localises at the midcell division ring, and this requires the presence of the ring-assembly protein FtsZ1. The division constriction protein FtsZ2 also influences the proper midcell assembly and structure of CdpA. In the absence of CdpA, cells frequently fail to divide properly, and FtsZ1 formed poorly condensed pseudo-helical structures spanning across a broad region of the cell, whereas FtsZ2 showed mispositioned foci, nano-rings, and filaments. The rate of directional movement of FtsZ1 and FtsZ2 structures around the division ring appears minimally affected by loss of CdpA, which resulted in continual repositioning of the aberrant FtsZ structures in the cells. In contrast to the FtsZ proteins, CdpA formed relatively immobile foci around the ring. Protein domain function studies, pull-down assays, and multimer structure predictions suggest that CdpA is part of a membrane complex that tethers FtsZ2 and other division proteins to the midcell membrane. Our discovery of an archaeal FtsZ organisation and midcell anchor protein offers new insights into cell division mechanisms that are similar across the tree of life.
许多古菌似乎通过两个FtsZ同源物（FtsZ1和FtsZ2）以及另一个细菌细胞分裂同源物（SepF）的协同活动进行分裂，这些蛋白是中细胞分裂环的一部分。在此，我们鉴定出一种额外的蛋白质（HVO_0739，重新命名为CdpA），它参与嗜盐栖热菌的细胞分裂，在其他嗜盐古菌中也有同源物。CdpA定位于中细胞分裂环，这需要环组装蛋白FtsZ1的存在。分裂缢缩蛋白FtsZ2也影响CdpA在中细胞的正确组装和结构。在没有CdpA的情况下，细胞经常无法正常分裂，FtsZ1形成了跨越细胞广泛区域的凝聚性差的假螺旋结构，而FtsZ2则显示出定位错误的焦点、纳米环和细丝。FtsZ1和FtsZ2结构围绕分裂环的定向移动速率似乎受CdpA缺失的影响最小，这导致细胞中异常FtsZ结构不断重新定位。与FtsZ蛋白不同，CdpA在环周围形成相对固定的焦点。蛋白质结构域功能研究、下拉分析和多聚体结构预测表明，CdpA是膜复合物的一部分，该复合物将FtsZ2和其他分裂蛋白 tether 到中细胞膜上。我们对古菌FtsZ组织和中细胞锚定蛋白的发现为生命之树上相似的细胞分裂机制提供了新的见解。
