TALENs技术的研究进展及其应用前景

Advances in transcription activator-like effectors - a review

摘要:

转录激活因子样效应物核酸酶 (Transcription activator-like effector nucleases, TALENs)，是一种将最初发现于植物病原菌的TALEs蛋白 (Transcription activator-like effectors, TALEs) 同限制性核酸内切酶的切割结构域 (例如FokⅠ) 融合而成的人工酶。TALENs的特异性取决于数量可变的串联重复单元，这也是TALEs特异性识别DNA的功能结构单元。理论上，人工构建的TALENs可以特异性识别任意DNA位点并使之断裂，进行基因敲除、插入或修饰。TALENs技术发展至今已经在多层次、多物种中获得成功。本文总结了TALENs技术的研究进展，及其与ZFNs、CRISPR/Cas等技术相较的优劣之处。TALENs在工业微生物育种领域具有特殊的应用优势，其载体构建便利、靶向精准、编辑效率高，以及拥有良好的生物安全性，具备推广应用的前景。

Abstract:

As a protein originally found in plant pathogenic bacteria, transcription activator-like effectors (TALEs) can fuse with the cleaving domain of restriction endonuclease (For example FokⅠ) to form artificial nucleases named TALENs. These proteins are dependent on variable numbers of tandem Repeats of TALEs to recognize and bind DNA sequences. Each of these repeats consists of a set of approximately 34 amino acids, composed of about 32 conserved amino acids and 2 highly variable amino acids called repeat variant di-residues (RVDs). RVDs distinguish one TALE from another and can make TALEs have a simple cipher for the one-to-one recognition for proteins and DNA bases. Based on this, in theory, artificially constructed TALENs could recognize and break DNA sites specifically and arbitrarily to perform gene knockout, insertion or modification. We reviewed the development of this technology in multi-level and multi species, and its advantages and disadvantages compared with ZFNs and CRISPR/Cas technology. We also address its special advantages in industrial microbe breeding, vector construction, targeting precision, high efficiency of editing and biological safety.