肺炎链球菌CcrZ蛋白在细胞周期调控中的作用

The Role of CcrZ Protein of Streptococcus pneumoniae in Cell Cycle Regulation

为了维持基因组稳定性,细胞在增殖过程中不仅需要对细胞周期各事件(DNA复制、DNA分离和细胞分裂)进行单独调控,还要将这些事件彼此协调起来。在细菌中,DNA复制起始和细胞分裂分别由复制起始蛋白DnaA和细胞分裂体(divisome)蛋白FtsZ负责,然而这两个过程的协调机制少有报道。最近在肺炎链球菌(Streptococcus pneumoniae)中发现一种细胞周期时空调节子CcrZ,其具有三个功能:(1)激活DnaA依赖的复制起始;(2)参与后期细胞分裂体的组装;(3)通过将Z环(Z-ring)适时定位在细胞中央以使DNA复制和细胞分裂相协调。基于CcrZ的结构和保守性,该文综述了以CcrZ为代表的多种蛋白调控DNA复制起始、Z环组装和定位的机制,并展望了多细胞周期事件协调子在相关领域的应用前景。

To maintain genomic stability,cells not only need to regulate cell cycle events(DNA replication,DNA segregation,and cell division)during proliferation respectively,they also need to coordinate these events with each other.In bacteria,DNA replication initiation and cell division are responsible for the replication initiation protein Dna A and the cell division divisome protein FtsZ,respectively.However,the mechanism of coordination of these two processes is rarely reported.A cell cycle spatiotemporal regulator CcrZ was recently discovered in Streptococcus pneumoniae,which has three functions:(1)CcrZ activates DnaA-dependent replication initiation;(2)CcrZ participates in the late-stage assembly of cell divisome;(3)CcrZ coordinates DNA replication and cell division by positioning the Z-ring at the midcell.Based on the structure and conservation of CcrZ,this paper reviews the mechanisms of various proteins represented by CcrZ in regulating DNA replication initiation,Z-ring assembly and Z-ring localization.It also prospects the application of coordinators of multipe cell cycle events in related fields.