ITCH E3 Ubiquitin Ligase Interacts with Ebola Virus VP40 To Regulate Budding

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• Ebola virus (EBOV) and Marburg virus (MARV) are filoviruses causing severe hemorrhagic fever with high mortality.
• The matrix protein VP40 is crucial for viral assembly, budding, and egress.
• VP40 utilizes late (L) budding domains to recruit host proteins, facilitating virus release.

Purpose of the Study:

• To identify novel host interactors of the EBOV VP40 protein.
• To investigate the role of the E3 ubiquitin ligase ITCH in EBOV VP40-mediated virus egress.
• To explore potential therapeutic targets for filovirus infections.

Main Methods:

• Investigated the interaction between the PPxY L domain motif of EBOV VP40 and the WW domain of host E3 ubiquitin ligase ITCH.
• Demonstrated the physical and functional interaction between ITCH and eVP40.
• Utilized virus-like particles (VLPs) to mimic viral budding and egress.

Main Results:

• Identified ITCH as a novel WW domain host interactor of EBOV VP40.
• Confirmed that the PPxY L domain of eVP40 specifically binds to the WW domain of ITCH.
• Showed that the interaction between eVP40 and ITCH facilitates VLP and virus budding and egress.
• Highlighted the role of cellular E3 ligases, ubiquitination, and VP40 in regulating virus egress.

Conclusions:

• The E3 ubiquitin ligase ITCH is a novel interactor of EBOV VP40 that regulates virus egress.
• This virus-host interaction provides a potential new target for small-molecule inhibitors to block filovirus budding.
• Understanding these interactions is critical for developing effective countermeasures against emerging filoviruses like EBOV.