VP0 Myristoylation Is Essential for Senecavirus A Replication

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• Many picornaviruses rely on myristoylation of capsid proteins for replication.
• N-myristoyltransferase (NMT) catalyzes this process, attaching a myristoyl group to the N-terminal glycine residue.
• NMT inhibitors like IMP-1088 and DDD85646 block NMT activity.

Purpose of the Study:

• To investigate if Senecavirus A (SVA) utilizes NMT for VP0 modification and viral replication.
• To determine the role of VP0 myristoylation in SVA propagation.

Main Methods:

• Utilized NMT inhibitors (IMP-1088, DDD85646) to assess their effect on SVA replication.
• Generated NMT1 knockout and overexpression cell lines (BHK-21) to study NMT1's role.
• Performed site-directed mutagenesis on the SVA VP0 N-terminus, focusing on the glycine and threonine residues.
• Analyzed viral replication, protein localization, and myristoylation status.

Main Results:

• NMT inhibitors significantly suppressed SVA replication.
• NMT1 knockout cells showed reduced viral replication, while NMT1 overexpression enhanced it, indicating VP0 is a potential NMT1 substrate.
• Myristoylation of SVA VP0 correlated with its cytoplasmic localization.
• Substitution of the N-terminal glycine residue resulted in a nonviable virus.
• The threonine residue at the fifth position of VP0 positively influenced SVA replication.

Conclusions:

• Senecavirus A VP0 myristoylation is essential for viral replication.
• NMT1 plays a critical role in SVA propagation, likely by facilitating VP0 myristoylation and proper subcellular localization.