Inhibition of 53BP1 favors homology-dependent DNA repair and increases CRISPR-Cas9 genome-editing efficiency.
Marella D CannyNathalie MoattiLeo C K WanAmélie Fradet-TurcotteDanielle KrasnerPedro A Mateos-GomezMichal ZimmermannAlexandre OrthweinYu-Chi JuangWei ZhangSylvie M NoordermeerEduardo SeclenMarcus D WilsonAndrew VorobyovMeagan MunroAndreas ErnstTimothy F NgTiffany ChoPaula M CannonSachdev S SidhuFrank SicheriDaniel DurocherPublished in: Nature biotechnology (2017)
Programmable nucleases, such as Cas9, are used for precise genome editing by homology-dependent repair (HDR). However, HDR efficiency is constrained by competition from other double-strand break (DSB) repair pathways, including non-homologous end-joining (NHEJ). We report the discovery of a genetically encoded inhibitor of 53BP1 that increases the efficiency of HDR-dependent genome editing in human and mouse cells. 53BP1 is a key regulator of DSB repair pathway choice in eukaryotic cells and functions to favor NHEJ over HDR by suppressing end resection, which is the rate-limiting step in the initiation of HDR. We screened an existing combinatorial library of engineered ubiquitin variants for inhibitors of 53BP1. Expression of one variant, named i53 (inhibitor of 53BP1), in human and mouse cells, blocked accumulation of 53BP1 at sites of DNA damage and improved gene targeting and chromosomal gene conversion with either double-stranded DNA or single-stranded oligonucleotide donors by up to 5.6-fold. Inhibition of 53BP1 is a robust method to increase efficiency of HDR-based precise genome editing.
Keyphrases
- genome editing
- crispr cas
- dna repair
- dna damage
- induced apoptosis
- cell cycle arrest
- endothelial cells
- copy number
- oxidative stress
- small molecule
- endoplasmic reticulum stress
- genome wide
- dna damage response
- cell death
- poor prognosis
- cell proliferation
- dna methylation
- pluripotent stem cells
- cancer therapy
- decision making