Role of the vacuolar ATPase in the Alphavirus replication cycle

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Alphaviruses can enter cells via direct plasma membrane penetration, bypassing endocytosis.
• Vacuolar ATPase (V-ATPase) regulates intracellular pH, essential for cellular processes.
• Bafilomycin A1 (BAF) is a specific inhibitor of V-ATPase activity.

Purpose of the Study:

• To investigate the role of V-ATPase in alphavirus replication.
• To characterize the impact of V-ATPase inhibition on Sindbis virus infection.

Main Methods:

• Generation of a Bafilomycin A1 (BAF)-resistant Sindbis virus mutant (BRSV).
• Comparison of BRSV and parent Sindbis virus replication in BAF-treated cells.
• Sequence analysis of the BRSV E2 glycoprotein to identify resistance mutations.

Main Results:

• BRSV exhibited increased production of mature virus and viral RNA in BAF-treated cells compared to the parent virus.
• Mutations (T15I/Y18H) in the E2 glycoprotein were identified as responsible for the BAF-resistant phenotype.
• A functional V-ATPase is necessary for efficient alphavirus RNA synthesis and virus maturation.

Conclusions:

• V-ATPase activity is required for optimal alphavirus RNA synthesis.
• V-ATPase plays a critical role in the maturation of infectious alphaviruses.
• Targeting V-ATPase could be a strategy to control alphavirus infections.