WWOX-Mediated Degradation of AMOTp130 Negatively Affects Egress of Filovirus VP40 Virus-Like Particles

Ebola virus (EBOV) and Marburg virus (MARV) continue to emerge and cause severe hemorrhagic disease in humans. A comprehensive understanding of the filovirus-host interplay will be crucial for identifying and developing antiviral strategies. The filoviral VP40 matrix protein drives virion assembly and egress, in part by recruiting specific WW domain-containing host interactors via its conserved PPxY late (L) domain motif to positively regulate virus egress and spread. In contrast to these positive regulators of virus budding, a growing list of WW domain-containing interactors that negatively regulate virus egress and spread have been identified, including BAG3, YAP/TAZ, and WWOX. In addition to host WW domain regulators of virus budding, host PPxY-containing proteins also contribute to regulating this late stage of filovirus replication. For example, angiomotin (AMOT) is a multi-PPxY-containing host protein that functionally interacts with many of the same WW domain-containing proteins that regulate virus egress and spread. In this report, we demonstrate that host WWOX, which negatively regulates egress of VP40 virus-like particles (VLPs) and recombinant vesicular stomatitis virus (VSV) M40 virus, interacts with and suppresses the expression of AMOT. We found that WWOX disrupts AMOT's scaffold-like tubular distribution and reduces AMOT localization at the plasma membrane via lysosomal degradation. In sum, our findings reveal an indirect and novel mechanism by which modular PPxY-WW domain interactions between AMOT and WWOX regulate PPxY-mediated egress of filovirus VP40 VLPs. A better understanding of this modular network and competitive nature of protein-protein interactions will help to identify new antiviral targets and therapeutic strategies. IMPORTANCE Filoviruses (Ebola virus [EBOV] and Marburg virus [MARV]) are zoonotic, emerging pathogens that cause outbreaks of severe hemorrhagic fever in humans. A fundamental understanding of the virus-host interface is critical for understanding the biology of these viruses and for developing future strategies for therapeutic intervention. Here, we reveal a novel mechanism by which host proteins WWOX and AMOTp130 interact with each other and with the filovirus matrix protein VP40 to regulate VP40-mediated egress of virus-like particles (VLPs). Our results highlight the biological impact of competitive interplay of modular virus-host interactions on both the virus life cycle and the host cell.