Mitochondrial DNA editing in mice with DddA-TALE fusion deaminases

Hyunji Lee,Jin-Soo Kim,Huiyun Seo,Beum-Chang Kang,Annie Kim,Seonghyun Lee,Gayoung Baek

doi:10.1038/s41467-021-21464-1

Hyunji Lee, Jin-Soo Kim + Show 5 more

Open Access

https://doi.org/10.1038/s41467-021-21464-1

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Abstract

DddA-derived cytosine base editors (DdCBEs), composed of the split interbacterial toxin DddAtox, transcription activator-like effector (TALE), and uracil glycosylase inhibitor (UGI), enable targeted C-to-T base conversions in mitochondrial DNA (mtDNA). Here, we demonstrate highly efficient mtDNA editing in mouse embryos using custom-designed DdCBEs. We target the mitochondrial gene, MT-ND5 (ND5), which encodes a subunit of NADH dehydrogenase that catalyzes NADH dehydration and electron transfer to ubiquinone, to obtain several mtDNA mutations, including m.G12918A associated with human mitochondrial diseases and m.C12336T that incorporates a premature stop codon, creating mitochondrial disease models in mice and demonstrating a potential for the treatment of mitochondrial disorders.

Highlights

DddA-derived cytosine base editors (DdCBEs), composed of the split interbacterial toxin DddAtox, transcription activator-like effector (TALE), and uracil glycosylase inhibitor (UGI), enable targeted C-to-T base conversions in mitochondrial DNA
We chose the Mus musculus mitochondrial ND5 gene encoding NADH-ubiquinone oxidoreductase chain 5 protein to demonstrate in vivo mitochondrial DNA (mtDNA) editing using our Golden-Gate assembly system
The ND5 protein is a core subunit of NADH dehydrogenase, which catalyzes the transfer of electrons from NADH to the respiratory chain

Summary

Introduction

DddA-derived cytosine base editors (DdCBEs), composed of the split interbacterial toxin DddAtox, transcription activator-like effector (TALE), and uracil glycosylase inhibitor (UGI), enable targeted C-to-T base conversions in mitochondrial DNA (mtDNA). Mok et al recently developed a base editing approach using the bacterial cytidine deaminase toxin, DddAtox, to demonstrate efficient C-to-T base conversions in vitro[6]. In this approach, split DddAtox nontoxic halves fused to transcription activator-like effector (TALE) proteins, which can be custom-designed to recognize predetermined target DNA sequences[7], form a functional cytosine deaminase within the editing window to induce C-to-T base editing at the target site in mtDNA. We investigate whether DdCBEs can achieve mtDNA base editing in vivo to create animal models with mitochondrial mutations and to show germline transmission of the resulting mitochondrial mutations in mice

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