Targeted manipulation of m 6 A RNA modification through CRISPR-Cas-based strategies.

N ⁶ -methyladenosine (m ⁶ A) is a reversible and prevalent internal modification in RNAs and can be dynamically modulated by methyltransferase and demethylase. Targeted manipulation of m ⁶ A RNA modification is critical in studying the functions of specific m ⁶ A sites as well as developing molecular therapies through targeting m ⁶ A. The CRISPR-Cas systems including CRISPR-Cas9 and CRISPR-Cas13 have been widely used to edit and modify specific nucleotides on DNA and RNA through fusing effective proteins such as enzymes with Cas9/13. Through taking advantage of the m ⁶ A methyltransferase and demethylase, a series of CRISPR-Cas-based methods have also been developed to manipulate the m ⁶ A methylation at specific RNA sites. This review summarizes the latest CRISPR-Cas13 and Cas9 toolkits for m ⁶ A site-specific manipulation, including fundamental components, on-target efficiency, editing window, PAM/PFS requirement, and subcellularly localized targeting as well as potential limitations. We thus aim to provide an overview to assist researchers to choose an optimal tool to manipulate m ⁶ A for different purposes and also point out possible optimization strategies.
(Copyright © 2022 Elsevier Inc. All rights reserved.)