Enhanced or reversible RNA N6-methyladenosine editing by red/far-red light induction.

The RNA N6-methyladenosine (m6A) modification is a critical regulator of various biological processes, but precise and dynamic control of m6A remains a challenge. In this work, we present a red/far-red light-inducible m6A editing system that enables efficient and reversible modulation of m6A levels with minimal off-target effects. By engineering the CRISPR dCas13 protein and sgRNA with two pairs of light-inducible heterodimerizing proteins, ΔphyA/FHY1 and Bphp1/PspR2, we achieved targeted recruitment of m6A effectors. This system significantly enhances m6A writing efficiency and allows dynamic regulation of m6A deposition and removal on specific transcripts, such as SOX2 and ACTB. Notably, reversible m6A editing was achieved through cyclic modulation at a single target site, demonstrating the ability to influence mRNA expression and modulate the differentiation state of human embryonic stem cells. This optogenetic platform offers a precise, versatile tool for cyclic and reversible m6A regulation, with broad implications for understanding RNA biology and its potential applications in research and medicine.