Decoding the interplay between m⁶A modification and stress granule stability by live-cell imaging.

Area of Science:

• Molecular Biology
• Cell Biology
• RNA Biology

Background:

• N6-methyladenosine (m6A) modification and its cytoplasmic reader proteins, YTHDFs, are known to interact with stress granules (SGs).
• The precise role of m6A modification and YTHDF proteins in regulating SG dynamics and mRNA translation under stress remains largely uncharacterized.

Purpose of the Study:

• To investigate the interplay between m6A modification and stress granule stability.
• To elucidate the mechanism by which YTHDF proteins influence SG dynamics and mRNA translation recovery.

Main Methods:

• Development and application of a spatiotemporal m6A imaging system (SMIS) for live-cell monitoring of m6A modification and mRNA translation.
• Utilizing SMIS to observe dynamic changes in m6A-modified mRNAs within SGs under arsenite stress.
• Employing knockdown of YTHDF2 to assess its impact on SG disassembly and mRNA redistribution.

Main Results:

• SMIS demonstrated dynamic enrichment of m6A-modified mRNAs into SGs under arsenite stress, followed by partitioning into the cytosol upon SG disassembly.
• Knockdown of YTHDF2 accelerated SG disassembly, leading to faster mRNA redistribution and recovery of stalled translation.
• YTHDF2 was found to regulate SG stability via interaction with G3BP1 in an m6A-modified RNA-dependent manner.

Conclusions:

• m6A modification and YTHDF2 play a crucial role in regulating stress granule stability.
• YTHDF2's interaction with G3BP1, dependent on m6A-modified RNA, mediates SG stability and translation recovery.
• This study reveals a novel mechanism linking m6A modification to stress granule dynamics and translational control.