Unconstrained Precision Mitochondrial Genome Editing with αDdCBEs.

Area of Science:

• Mitochondrial genetics
• Molecular biology
• Gene editing technologies

Background:

• DddA-derived cytosine base editors (DdCBEs) target C•G-to-T•A conversions in mitochondrial DNA (mtDNA), crucial for understanding cellular processes and treating genetic disorders.
• TALE-based DdCBEs face limitations due to a 5'-T constraint, restricting editing to over 150 human mtDNA loci.

Approach:

• Engineered modified TALE proteins in αDdCBEs to recognize all 5' bases, challenging the 5'-T constraint.
• Assessed the activity and specificity of αDdCBEs compared to conventional DdCBEs across diverse mtDNA loci.
• Validated the compatibility of αDdCBEs with DddA derivatives and TALE shifting for optimized base editing.

Key Points:

• αDdCBEs successfully edited mtDNA at diverse loci, irrespective of the 5'-most base.
• αDdCBEs demonstrated superior activity and specificity compared to conventional DdCBEs.
• The 5'-T constraint for TALE-based mtDNA editing was overcome, expanding editable sites.

Conclusions:

• αDdCBEs enable efficient, specific, and unconstrained base editing in mtDNA.
• This technology broadens the scope of potential therapeutic applications for mitochondrial genetic disorders.
• The development of αDdCBEs represents a significant advancement in mitochondrial gene editing tools.