Epigenetic Control of Toehold-Mediated Strand Displacement for Programmable Molecular Circuit Regulation and Enhanced...

Area of Science:

• Biochemistry
• Molecular Biology
• Synthetic Biology

Background:

• Dynamic DNA nanotechnology relies on toehold-mediated strand displacement.
• Current methods face limitations in precise kinetic control due to fixed toehold stability.

Purpose of the Study:

• To develop a novel system for programmable kinetic control of DNA strand displacement using epigenetic modifications.
• To demonstrate the application of this system in enhancing nucleic acid circuit function and microRNA detection.

Main Methods:

• Exploiting single-nucleobase N⁶-methyladenosine (m⁶A) modification within DNA toehold domains.
• Utilizing the demethylase FTO to reversibly modulate m⁶A modifications and toehold reactivity.
• Applying the system to catalytic hairpin assembly for microRNA detection and intracellular imaging.

Main Results:

• Site-specific m⁶A methylation was shown to inhibit DNA strand displacement rates by disrupting toehold base pairing.
• Demethylase FTO precisely and reversibly controlled reaction kinetics.
• The system enhanced sensitivity and specificity in microRNA-21 detection, enabling intracellular imaging.

Conclusions:

• Epigenetic regulation via single-base m⁶A modifications offers a versatile tool for chemical system design.
• This platform provides a general framework for dynamic nucleic acid circuits with broad applications in biosensing and molecular computing.
• The findings advance the development of epigenetically controlled biochemical systems.