N-Acetyltransferase 8 Promotes Viral Replication by Increasing the Stability of Enterovirus 71 Nonstructural Proteins.

Enterovirus 71 (EV71) is deemed a reemergent pathogen, with recent outbreaks worldwide. EV71 infection causes hand, foot, and mouth disease (HFMD) and has been associated with severe cardiac and central nervous system complications and even death. Viruses need host factors to complete their life cycle; therefore, the identification of the host factors for EV71 infection is pivotal to new antiviral research. Emerging evidence has highlighted the importance of protein acetylation during infection by various human viruses. The endoplasmic reticulum (ER), as the prominent organelle of EV71 replication, also has a unique acetylation regulation mechanism. However, the pathogenesis of EV71 and its relationship with the ER-based acetylation machinery are not fully understood. In this study, we demonstrated for the first time that the ER-resident acetyltransferase N-acetyltransferase 8 (NAT8) is a host factor for EV71 infection. Inhibiting NAT8 with CRISPR or a small compound significantly suppressed EV71 infection in SK-N-SH cells. NAT8 promoted EV71 replication in an acetyltransferase-activity-dependent manner. Additionally, we found that NAT8 facilitates EV71 infection by interacting with EV71 2B, 3AB, and 3C proteins and increasing the stability of these proteins. These results uncovered a novel function of NAT8 and elucidated a new mechanism underlying the regulation of EV71 replication. IMPORTANCE EV71 is one of the most common pathogens causing HFMD in young children, and some patients experience severe or fatal neurological consequences. To ensure efficient replication, the virus must hijack multiple host factors for its own benefit. Here, we show that the ER-resident acetyltransferase NAT8 is a host factor for EV71 infection. EV71 fails to complete its infection in various cells in the absence of NAT8. We further show that NAT8 benefits EV71 replication in an acetyltransferase-activity-dependent manner. Finally, we show that NAT8 facilitates EV71 infection by interacting with EV71 2B, 3AB, and 3C proteins and increasing the stability of these proteins. These results uncovered a novel function of NAT8 in EV71 infection and elucidated a new mechanism underlying the regulation of EV71 replication.