Pathways and assays for DNA double-strand break repair by homologous recombination  

作　　者：Jinbao Li Huize Sun Yulin Huang Yali Wang Yuyan Liu Xuefeng Chen 

机构地区：[1]Hubei Key Laboratory of Cell Homeostasis,College of Life Sciences and the Institute for Advanced Studies,Wuhan University,Wuhan 430072,China

出　　处：《Acta Biochimica et Biophysica Sinica》2019年第9期879-889,共11页生物化学与生物物理学报（英文版）

基　　金：This work is supported by the grants from the National Natural Science Foundation of China(Nos.31671294 and 31872808);the National Basic Key Research Program of China(No.2015CB910602);National Thousand Young Talents Program to X.C.;We thank Dr Xiangwei He(Zhejiang University,Hangzhou,China)for critical reading of the manuscript.

摘　　要：Double strand breaks(DSBs)are the most detrimental type of DNA damage that must be repaired to ensure genome integrity and cell survival.Unrepaired or improperly repaired DSBs can potentially cause tumorigenesis or cell death.DSBs are primarily repaired by non-homologous end joining or homologous recombination(HR).The HR pathway is initiated by processing of the 5′-end of DSBs to generate 3′-end single-strand DNA(ssDNA).Furthermore,the intermediate is channeled to one of the HR sub-pathways,including:(i)double Holliday junction(dHJ)pathway,(ii)synthesis-dependent strand annealing(SDSA),(iii)break-induced replication(BIR),and(iv)single-strand annealing(SSA).In the dHJ sub-pathway,the 3′-ssDNA coated with Rad51 recombinase performs homology search and strand invasion,forming a displacement loop(D-loop).Capture of the second end by the D-loop generates a dHJ intermediate that is subsequently dissolved by DNA helicase or resolved by nucleases,producing non-crossover or crossover products.In SDSA,the newly synthesized strand is displaced from the D-loop and anneals to the end on the other side of the DSBs,producing non-crossovers.In contrast,BIR repairs one-end DSBs by copying the sequence up to the end of the template chromosome,resulting in translocation or loss of heterozygosity.SSA takes place when resection reveals flanking homologous repeats that can anneal,leading to deletion of the intervening sequences.A variety of reporter assays have been developed to monitor distinct HR sub-pathways in both Saccharomyces cerevisiae and mammals.Here,we summarize the principles and representative assays for different HR sub-pathways with an emphasis on the studies in the budding yeast.

关 键 词：double-strand break HOMOLOGOUS recombination synthesis-dependent STRAND ANNEALING break-induced REPLICATION SINGLE-STRAND ANNEALING 

分 类 号：R73[医药卫生—肿瘤]