β-Coronaviruses exploit ESCRT for virion assembly and egress

ABSTRACT β-Coronaviruses assemble at the endoplasmic reticulum-to-Golgi compartment and exit cells through the lysosomal trafficking pathway. However, the molecular mechanisms of virion assembly and egress are largely unknown. Here, we report that β-coronaviruses recruit endosomal sorting complexes required for transport (ESCRTs) to facilitate virion assembly and egress. The viral proteins N and M interacted with ESCRT components TSG101 and VPS28, respectively. Electron microscopy analysis revealed that virion assembly was disrupted by TSG101 knockdown at an early stage and by VPS28 knockdown at a late stage. Knockdown of ESCRT components MVB12A and CHMP6 did not affect virion assembly but inhibited virion egress. Downregulation of these ESCRT factors or VPS4A, or treatment of cells with the TSG101 antagonist tenatoprazole significantly inhibited the production of the virion-like particles of β-coronaviruses and the replication of human coronavirus OC43. These findings indicate that β-coronaviruses exploit ESCRT for virion assembly and egress and suggest that the interaction interface between ESCRT and the viruses could be a target for the development of broad-spectrum anti-coronavirus therapeutics. IMPORTANCE β-Coronaviruses have caused disastrous pandemics and may cause serious pandemics in the future. Virion assembly and egress are critical steps in the life cycle of coronaviruses. However, despite extensive studies in the past few years, the molecular mechanisms for virion assembly and egress are still largely unknown. Here we show that β-coronaviruses recruit ESCRT components TSG101 and VPS28 for virion assembly and that ESCRT components MVB12A and CHMP6 are required for virion egress. Treatment of cells with the TSG101 antagonist inhibited the assembly of multiple β-coronaviruses. These findings indicate that ESCRT participates in β-coronavirus assembly and egress and might be a potential target for the development of broad-spectrum anti-coronavirus therapeutics.