真核细胞染色体DNA复制起始及复制叉稳定性维持的机制  

Mechanisms of Chromosomal DNA Replication Initiation and Stabilization of Replication Forks in Eukaryotes

作　　者：吴丽虹[1] 刘阳[1] 孔道春[1] 

机构地区：[1]北京大学生命科学学院,蛋白质与植物基因研究国家重点实验室,北京100871

出　　处：《中国科学：生命科学》2013年第10期824-832,共9页Scientia Sinica(Vitae)

基　　金：国家自然科学基金(批准号:31170739);国家重点基础研究发展计划(批准号:2010CB912201)资助项目

摘　　要：在真核生物中，DNA复制在染色体上特定的多位点起始．当细胞处在晚M及G1期，多个复制起始蛋白依次结合到DNA复制源，组装形成复制前复合体．pre．RC在Gl-S的转折期得到激活，随后，多个直接参与DNA复制又形成的蛋白结合到DNA复制源，启动DNA的复制，形成两个双向的DNA复制又．在染色体上，移动的DNA复制又经常会碰到复制障碍（二级DNA结构、一些蛋白的结合位点、损伤的碱基等）而暂停下来，此时，需要细胞周期检验点的调控来稳定复制叉，否则，会导致复制又垮塌及基因组不稳定．本文就真核细胞染色体DNA复制起始的机制，以及复制又稳定性的维持机制进行简要综述．In eukaryotes, DNA replication initiates at multiple and specific sites on chromosomal DNA. When cells are in late M and G1 phases, Cdc6/Cdcl8, Cdtl and MCM are loaded to ORC binding sites on DNA replication origins to form pre-RC （pre-replication complex）. Pre-RC is activated at the transition of G1 to S phase. Subsequently, those proteins that act at replication forks bind to DNA origins to form two bidirectional replication forks for initiating DNA synthesis. On chromosome, the moving replication forks often encounter replication fork barriers （DNA secondary structure, some protein binding sites, damaged bases） and stall. The stalled forks require checkpoint control to maintain fork stability; otherwise, stalled forks will collapse and genomic integrity is compromised. This article gives a brief review about current understanding of the mechanism of replication initiation and replication fork stabilization.

关 键 词：DNA复制源 pre-RC组装 复制叉稳定性 S期细胞周期检验点 

分 类 号：Q343[生物学—遗传学]