Exo70 promotes herpesvirus secretory vesicle tethering and virion release in an exocyst complex-dependent manner

Abstract

The exocyst complex, a multisubunit protein complex, mediates secretory vesicles fusion with the plasma membrane (PM) to deliver materials to the cell surface or to release cargoes to the extracellular space, but whether it is related to viral secretory vesicles tethering and virion release is unknown. Here, we identified that the exocyst complex subunit Exo70 promotes the trafficking of herpesvirus secretory vesicles and the release of mature virions in an exocyst complex-dependent manner. Mechanistically, mutation of Exo70 Lys632 and Lys635 diminishes viral secretory vesicles anchoring to PM. Moreover, the small GTPase Rab11a is necessary for the transport of viral secretory vesicles, and the Snapin-Exo70-SNAP23 axis is involved in fusion of viral secretory vesicles to the PM and release of virions. Most significantly, we discovered that Endosidin2 (ES2), an inhibitor of exocytosis via the exocyst complex, provides protection against herpesvirus infection in cells and mice. Overall, these findings unveil a previously uncharacterized role and mechanism of the exocyst complex in viral replication, highlighting its potential as an effective strategy against herpesvirus infection.