TAL效应子介导基因组DNA的靶向修饰  

Targeted Modification of Genomic DNA by TALEs

作　　者：庄军[1] 吴祖建[1] 

机构地区：[1]福建农林大学植物病毒研究所福建省植物病毒学重点实验室,福州350002

出　　处：《中国生物工程杂志》2014年第8期74-80,共7页China Biotechnology

基　　金：国家自然科学基金资助项目(31301641)

摘　　要：植物黄单胞菌病原细菌分泌的TAL效应子(Transcription activator-like effector)可结合特异的双链DNA。TAL是由序列几乎相同的多个DNA结合域的重复串联而构成的,每个DNA结合模块的重复可变双残基特异识别一个DNA碱基。TAL和核酸修饰相关功能域融合而成的定制TAL效应子(dTALE)能特定靶向修饰基因组DNA,在新近遗传工程中扮演重要角色。目前,TAL效应子与核酸酶FokI融合成的TALEN核酸酶(TALEN)能够靶向识别基因组位点并由核酸酶切割双链DNA造成双链断裂,通过同源重组(HR)或非同源末端连接(NHEJ)进行双链修复从而引发特定位点的基因突变。TALENs在多个模式生物中都具有较高的靶向有效性,而且TAL效应子DNA结合域可进行模块化设计,能够发展成高通量的基因靶向修饰和调控的平台,具有广阔的实际应用前景。对TAL效应子特异识别DNA的结构分析、TALENs的设计策略以及TAL效应子在基因组靶向修饰中的应用与展望等方面进行了概述。TAL（transcription activator-like） effectors secreted by plant pathogenic bacteria of genus Xanthomonasis capable of binding to specific genomic dsDNA. TAL is composed of modular architectures of DNA binding domains encompassing a tandem array of several almost identical repeat sequences. dTALEs（ designed TALEs） restructured with TAL effector and other nucleotide acid-binding domains（ such as nuclease,activator and suppressor） can specifically target and modify specific genomic DNA sequence,and play a pivotal role in genetic engineering. The repeat variable diresidues（ RVDs） in each TAL repeat is exclusively responsible for recognition of single DNA base. TALENs consisting of TAL and restriction enzyme Fok I can contact with the specifical genomic DNA site and undergo the cleavage of dsDNA. The resulting double-stranded breaks usually are remedied through HR（ homologous recombination） and NHEJ（ non-homologous end joining） and elicit corresponding gene mutations. TALENs are capable of generating highly efficient mutation in many model organisms. In virtue of modular design of the DNA-binding domain from TALEN system,TALENs can be developed into high-throughput platforms for gene modification and regulation and have broad-spectrum applications. Herein,an overview of the state-of-the-art structural advance of the TAL effectors,the design strategy for TALENs and applications and perspectives of TAL effector in genome-targeting modification and so on were provided.

关 键 词：TAL效应子 TAL效应子核酸酶 重复可变双残基 靶向突变 

分 类 号：Q789[生物学—分子生物学]