hnRNPA1 impedes snakehead vesiculovirus replication via competitively disrupting viral phosphoprotein-nucleoprotein interaction and degrading viral phosphoprotein

Heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) plays an important role in regulating the replication of many viruses. However, it remains elusive whether and how hnRNPA1 regulates fish virus replication. In this study, the effects of twelve hnRNPs on the replication of snakehead vesiculovirus (SHVV) were screened. Three hnRNPs, one of which was hnRNPA1, were identified as anti-SHVV factors. Further verification showed that knockdown of hnRNPA1 promoted, while overexpression of hnRNPA1 inhibited, SHVV replication. SHVV infection reduced the expression level of hnRNPA1 and induced the nucleocytoplasmic shuttling of hnRNPA1. Besides, we found that hnRNPA1 interacted with the viral phosphoprotein (P) via its glycine-rich domain, but not with the viral nucleoprotein (N) or large protein (L). The hnRNPA1-P interaction competitively disrupted the viral P-N interaction. Moreover, we found that overexpression of hnRNPA1 enhanced the polyubiquitination of the P protein and degraded it through proteasomal and lysosomal pathways. This study will help understanding the function of hnRNPA1 in the replication of single-stranded negative-sense RNA viruses and providing a novel antiviral target against fish rhabdoviruses.

Automated summary

In this study, twelve hnRNPs were screened for their effects on the replication of snakehead vesiculovirus (SHVV). Three hnRNPs, including hnRNPA1, were identified as anti-SHVV factors. Knockdown of hnRNPA1 promoted SHVV replication, while overexpression of hnRNPA1 inhibited it. Furthermore, hnRNPA1 was found to interact with the viral phosphoprotein (P) and disrupt the viral P-N interaction. Overexpression of hnRNPA1 also enhanced the polyubiquitination and degradation of the P protein.