Decoding the interplay between m ⁶ A modification and stress granule stability by live-cell imaging

<i>N</i>⁶-methyladenosine (m⁶A)-modified mRNAs and their cytoplasmic reader YTHDFs are colocalized with stress granules (SGs) under stress conditions, but the interplay between m⁶A modification and SG stability remains unclear. Here, we presented a spatiotemporal m⁶A imaging system (SMIS) that can monitor the m⁶A modification and the translation of mRNAs with high specificity and sensitivity in a single live cell. SMIS showed that m⁶A-modified reporter mRNAs dynamically enriched into SGs under arsenite stress and gradually partitioned into the cytosol as SG disassembled. SMIS revealed that knockdown of YTHDF2 contributed to SG disassembly, resulting in the fast redistribution of mRNAs from SGs and rapid recovery of stalled translation. The mechanism is that YTHDF2 can regulate SG stability through the interaction with G3BP1 in m⁶A-modified RNA-dependent manner. Our results suggest a mechanism for the interplay between m⁶A modification and SG through YTHDF2 regulation.