VP40 Protein, Zaire ebolavirus (H269L)

The VP40 protein plays a vital role in virus particle assembly and budding, orchestrating complex interactions with both viral and host components. It engages in a multifaceted network by interacting with the viral ribonucleocapsid and various host proteins of the ESCRT system, including VPS4, PDCD6IP/ALIX, NEDD4, or TGS101, crucial for efficient budding. The association with host E3 ubiquitin ligase SMURF2 further facilitates virus budding. Additionally, VP40's involvement extends to immune cell dysfunction, as it can be packaged into exosomes, reducing the viability of recipient cells through RNAi suppression and exosome-bystander apoptosis. Existing in different oligomeric forms, such as homodimers, homohexamers critical for budding, and homooctamers involved in genome replication and RNA binding, VP40 exhibits dynamic structural transitions. Notably, its interaction with various host factors, including TSG101, NEDD4, PDCD6IP/ALIX, SMURF2, and ITCH, highlights the complexity of VP40-mediated processes, shedding light on its central role in the intricate machinery governing virus assembly and egress.