Genome-Wide Screen Reveals Valosin-Containing Protein Requirement for Coronavirus Exit from Endosomes

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Coronaviruses, like SARS and MERS, pose significant public health threats due to their zoonotic potential and host-switching capabilities.
• Understanding the cellular machinery supporting coronavirus replication is crucial for developing effective interventions.

Purpose of the Study:

• To identify novel host factors essential for coronavirus replication using a genome-wide screening approach.
• To elucidate the specific roles of identified host factors in the viral life cycle, including interactions with viral components.

Main Methods:

• Genome-wide small interfering RNA (siRNA) screening was employed to identify host genes supporting infectious bronchitis virus (IBV) replication in human cells.
• Network analysis was used to map interactions between identified host factors and viral proteins, focusing on processes like RNA splicing, membrane trafficking, and ubiquitin conjugation.

Main Results:

• 83 novel host genes supporting IBV replication were identified.
• 30 of these genes form a network involved in RNA splicing, membrane trafficking, and ubiquitin conjugation.
• Valosin-containing protein (VCP/p97) was found to be critical for early infection steps, specifically inhibiting nucleocapsid N protein degradation and preventing viral accumulation in early endosomes.

Conclusions:

• The study identified numerous host factors that may be targeted for antiviral therapies against coronaviruses.
• Valosin-containing protein (VCP/p97) plays an unexpected role in regulating viral nucleocapsid protein stability and endosomal trafficking, suggesting it as a potential therapeutic target.