SARS-CoV-2 N Protein Hijacks the m6A Reader YTHDF2 to Suppress Antiviral Gene Expression.

The m6A RNA methylation pathway plays a critical role in host antiviral defense. Host cells employ m6A readers such as YTHDF2 to regulate viral RNA fate through diverse mechanisms, including degradation, translational control, and immune recognition. However, we found that YTHDF2 is essential for SARS-CoV-2 replication, suggesting that a virus may exploit this host machinery to its advantage. Through integrative RNA-proteome analysis, we identified the SARS-CoV-2 nucleocapsid (N) transcript as the most heavily m6A-modified viral transcript and a direct interactor of YTHDF2. The N protein forms a complex with YTHDF2 in the cytoplasm and redirects this host RNA decay machinery toward host antiviral transcripts. N suppresses ISG15, IFIT1, MX1 and pro-inflammatory cytokines in a largely YTHDF2-dependent manner, an effect that is lost in YTHDF2-knockout cells. These findings reveal a viral immune evasion strategy wherein a viral protein actively hijacks an m6A reader to silence antiviral gene expression, establishing the N-YTHDF2 axis as a therapeutic target against SARS-CoV-2 and other coronaviruses.