MiRNA-Responsive CRISPR-Cas System via a DNA Regulator.

Area of Science:

• Molecular Biology
• Biotechnology
• Genetics

Background:

• Clustered regularly interspaced short palindromal repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) is a versatile genome editing tool.
• Existing methods for regulating CRISPR-Cas9 activity often involve complex engineering.
• There is a need for simple and convenient regulatory systems for CRISPR-Cas9 technology.

Purpose of the Study:

• To devise a simple and convenient CRISPR activation system regulated by microRNAs (miRNAs).
• To create a DNA regulator that can be activated by specific miRNAs, thereby controlling CRISPR-Cas9 activity.

Main Methods:

• Designed a DNA regulator with two components: an inhibition component (PAM and seed sequence) that binds to the Cas9-ribonucleoprotein (RNP) complex, and an miRNA recognition component.
• The miRNA recognition component features a toehold DNA for target miRNA binding and a partially double-stranded DNA for miRNA complementarity.
• Upon binding of target miRNAs, the regulator's structure is disrupted, leading to its dissociation from the RNP complex and restoration of CRISPR activity.

Main Results:

• The developed system successfully demonstrated miRNA-activated regulation of CRISPR-Cas9 activity.
• The DNA regulator effectively inhibited Cas9-RNP complex activity until target miRNA binding occurred.
• The system showed potential for application to various miRNAs through simple sequence modifications.

Conclusions:

• This study presents a general and adaptable platform for controlled genome editing using a miRNA-activated CRISPR system.
• The developed system offers a simple and convenient method for regulating CRISPR-Cas9 activity.
• This approach facilitates precise genetic manipulation by enabling miRNA-specific control over genome editing processes.