Dividing the Archaeal Way: The Ancient Cdv Cell-Division Machinery.
Dividing the Archaeal Way: The Ancient Cdv Cell-Division Machinery.
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DOI：
10.3389/fmicb.2018.00174
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发表时间：
2018
影响因子：
5.2
通讯作者：
Dekker C
中科院分区：
文献类型：
--
作者：
Caspi Y;Dekker C
在大多数原核生物中，细胞分裂是由研究充分的fts基因介导的，其中FtsZ是主要参与者。然而，在许多古细菌物种中，分裂的方式是不同的。古细菌的Crenarchaeota门的特征是三种蛋白质CdvABC的作用。这种Cdv系统是一种独特的、研究较少的划分机制，值得进一步研究。在体内，三种Cdv蛋白形成复合带，其伴随隔膜形成而收缩。在三种Cdv蛋白中，CdvA是第一个被招募到分裂位点的，而CdvB和CdvC被认为参与了Cdv分裂机制的活性部分。有趣的是，CdvB与真核ESCRT-III复合物的蛋白质家族具有同源性，CdvC是真核Vps 4复合物的同源物。这两个真核复合物是ESCRT途径中的关键因子，ESCRT途径负责真核细胞中的各种出芽过程，并参与后生动物分裂的最后阶段。在那里，ESCRT-III形成主动切割膜的收缩机制，而作为ATP酶的Vps 4是ESCRT膜-解离聚合物周转所必需的。与CdvB和CdvC相反，CdvA是古菌Crenarchaeota和Thaumarchaeota门所特有的。Crenarchaeota分裂机制通常被认为是ESCRT分裂机制的简化版本，从而为研究高等生物细胞分裂的进化和机制提供了模型系统。然而，关于这种平行性和Crenarchaeota的分裂机制仍然存在许多悬而未决的问题。在这里，我们回顾了现有的数据的Cdv蛋白在Crenarchaeota的分裂过程中的作用，以及简要回顾ESCRT系统在真核生物中。我们调查的相似性和差异的分裂和分离机制在这两种情况下。我们认为，Cdv系统的功能不同，在古细菌比ESCRT在真核生物中，而且，与真核生物的情况不同，Cdv系统的主要功能可能与过剩的膜内陷和细胞壁合成。
Cell division in most prokaryotes is mediated by the well-studied fts genes, with FtsZ as the principal player. In many archaeal species, however, division is orchestrated differently. The Crenarchaeota phylum of archaea features the action of the three proteins, CdvABC. This Cdv system is a unique and less-well-studied division mechanism that merits closer inspection. In vivo, the three Cdv proteins form a composite band that contracts concomitantly with the septum formation. Of the three Cdv proteins, CdvA is the first to be recruited to the division site, while CdvB and CdvC are thought to participate in the active part of the Cdv division machinery. Interestingly, CdvB shares homology with a family of proteins from the eukaryotic ESCRT-III complex, and CdvC is a homolog of the eukaryotic Vps4 complex. These two eukaryotic complexes are key factors in the endosomal sorting complex required for transport (ESCRT) pathway, which is responsible for various budding processes in eukaryotic cells and which participates in the final stages of division in Metazoa. There, ESCRT-III forms a contractile machinery that actively cuts the membrane, whereas Vps4, which is an ATPase, is necessary for the turnover of the ESCRT membrane-abscission polymers. In contrast to CdvB and CdvC, CdvA is unique to the archaeal Crenarchaeota and Thaumarchaeota phyla. The Crenarchaeota division mechanism has often been suggested to represent a simplified version of the ESCRT division machinery thus providing a model system to study the evolution and mechanism of cell division in higher organisms. However, there are still many open questions regarding this parallelism and the division mechanism of Crenarchaeota. Here, we review the existing data on the role of the Cdv proteins in the division process of Crenarchaeota as well as concisely review the ESCRT system in eukaryotes. We survey the similarities and differences between the division and abscission mechanisms in the two cases. We suggest that the Cdv system functions differently in archaea than ESCRT does in eukaryotes, and that, unlike the eukaryotic case, the Cdv system's main function may be related to surplus membrane invagination and cell-wall synthesis.