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Characterization and Regulation of Cell Cycle-independent Noncanonical Gene Targeting

Overview
Journal Nat Commun
Specialty Biology
Date 2024 Jun 18
PMID 38890315
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Abstract

Homology-dependent targeted DNA integration, generally referred to as gene targeting, provides a powerful tool for precise genome modification; however, its fundamental mechanisms remain poorly understood in human cells. Here we reveal a noncanonical gene targeting mechanism that does not rely on the homologous recombination (HR) protein Rad51. This mechanism is suppressed by Rad52 inhibition, suggesting the involvement of single-strand annealing (SSA). The SSA-mediated gene targeting becomes prominent when DSB repair by HR or end-joining pathways is defective and does not require isogenic DNA, permitting 5% sequence divergence. Intriguingly, loss of Msh2, loss of BLM, and induction of a target-site DNA break all significantly and synergistically enhance SSA-mediated targeted integration. Most notably, SSA-mediated integration is cell cycle-independent, occurring in the G1 phase as well. Our findings provide unequivocal evidence for Rad51-independent targeted integration and unveil multiple mechanisms to regulate SSA-mediated targeted as well as random integration.

References
1.
Stark J, Pierce A, Oh J, Pastink A, Jasin M . Genetic steps of mammalian homologous repair with distinct mutagenic consequences. Mol Cell Biol. 2004; 24(21):9305-16. PMC: 522275. DOI: 10.1128/MCB.24.21.9305-9316.2004. View

2.
Symington L . Role of RAD52 epistasis group genes in homologous recombination and double-strand break repair. Microbiol Mol Biol Rev. 2002; 66(4):630-70, table of contents. PMC: 134659. DOI: 10.1128/MMBR.66.4.630-670.2002. View

3.
Yasuhara T, Kato R, Hagiwara Y, Shiotani B, Yamauchi M, Nakada S . Human Rad52 Promotes XPG-Mediated R-loop Processing to Initiate Transcription-Associated Homologous Recombination Repair. Cell. 2018; 175(2):558-570.e11. DOI: 10.1016/j.cell.2018.08.056. View

4.
Tucker K, Beard C, Dausmann J, Laird P, Lei H, Li E . Germ-line passage is required for establishment of methylation and expression patterns of imprinted but not of nonimprinted genes. Genes Dev. 1996; 10(8):1008-20. DOI: 10.1101/gad.10.8.1008. View

5.
Sakaue-Sawano A, Yo M, Komatsu N, Hiratsuka T, Kogure T, Hoshida T . Genetically Encoded Tools for Optical Dissection of the Mammalian Cell Cycle. Mol Cell. 2017; 68(3):626-640.e5. DOI: 10.1016/j.molcel.2017.10.001. View