Characterization of ACTN4 as a novel antiviral target against SARS-CoV-2

The various mutations in severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)pose a substantial challenge in mitigating the viral infectivity.The identification of novel host factors influencing SARS-CoV-2 replication holds potential for discovering new targets for broad-spectrum antiviral drugs that can combat future viral mutations.In this study,potential host factors regulated by SARS-CoV-2 infection were screened through different high-throughput sequencing techniques and further identified in cells.Subsequent analysis and experiments showed that the reduction of m6A modification level on ACTN4(Alpha-actinin-4)mRNA leads to a decrease in mRNA stability and translation efficiency,ultimately inhibiting ACTN4 expression.In addition,ACTN4 was demonstrated to target nsp12 for binding and characterized as a competitor for SARS-CoV-2 RNA and the RNA-dependent RNA polymerase complex,thereby impeding viral replication.Furthermore,two ACTN4 agonists,YS-49 and demethyl-coclaurine,were found to dose-dependently inhibit SARS-CoV-2 infection in both Huh7 cells and K18-hACE2 transgenic mice.Collectively,this study unveils the pivotal role of ACTN4 in SARS-CoV-2 infection,offering novel insights into the intricate interplay between the virus and host cells,and reveals two potential candidates for future anti-SARS-CoV-2 drug development.