title: Designed nucleases for targeted genome editing.
abstract: Targeted genome-editing technology using designed nucleases has been evolving rapidly, and its applications are widely expanding in research, medicine and biotechnology. Using this genome-modifying technology, researchers can precisely and efficiently insert, remove or change specific sequences in various cultured cells, micro-organisms, animals and plants. This genome editing is based on the generation of double-strand breaks (DSBs), repair of which modifies the genome through nonhomologous end-joining (NHEJ) or homology-directed repair (HDR). In addition, designed nickase-induced generation of single-strand breaks can also lead to precise genome editing through HDR, albeit at relatively lower efficiencies than that induced by nucleases. Three kinds of designed nucleases have been used for targeted DSB formation: zinc-finger nucleases, transcription activator-like effector nucleases, and RNA-guided engineered nucleases derived from the bacterial clustered regularly interspaced short palindromic repeat (CRISPR)-Cas (CRISPR-associated) system. A growing number of researchers are using genome-editing technologies, which have become more accessible and affordable since the discovery and adaptation of CRISPR-Cas9. Here, the repair mechanism and outcomes of DSBs are reviewed and the three types of designed nucleases are discussed with the hope that such understanding will facilitate applications to genome editing.
authors.affiliation: Department of Physiology and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Junwon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.|Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.
authors.forename: Jae-Hee
authors.initials: JH
authors.lastname: Chung
authors.affiliation: Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.
authors.forename: Ho Min
authors.initials: HM
authors.lastname: Kim
authors.affiliation: Department of Physiology and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Pharmacology and Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.|Graduate Program of Nano Science and Technology, Yonsei University, Seoul, Korea.
authors.forename: Hyongbum
authors.initials: H
authors.lastname: Kim
mesh_terms: D001483:Base Sequence; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000235:genetics; D004720:Endonucleases / Q000378:metabolism*; D000072669:Gene Editing; D005818:Genetic Engineering; D018745:Genome, Plant
chemical_list: D004720:Endonucleases
keywords: CRISPR-Cas9; double-strand break; homology-directed repair; nonhomologous end-joining; transcription activator-like effector nuclease; zinc-finger nuclease