Roles of the Picornaviral 3C Proteinase in the Viral Life Cycle and Host Cells

Sun, Di; Chen, Shun; Cheng, Anchun; Wang, Mingshu

Understanding the structure and functions of 3C pro provides accurate information for the design of broad-spectrum anti-picornaviral inhibitors. The development of irreversible inhibitors and the discovery of non-covalent inhibitors of 3C pro will accelerate the treatments for infection by picornaviruses and other viruses encoding 3CL pro . Due to the limitations involved with using killed whole virus, recombinant empty capsids, which are structural and immunogenic mimics of virus particles, have become a research hotspot for an alternate vaccine. The development and the production of empty capsids is dependent on 3C pro levels [3, 151] . 3C pro is well known to be a crucial proteinase for processing polyprotein and RNA-binding protein in viral replication. However, there is little information to date regarding the molecular mechanism by which 3C pro blocks various cellular pathways. Comparison of 3C pro functions in the life cycles of the host cell and virus can provide more insight into the pathogenesis and regulatory mechanisms of picornavirus. Comparison of 3C pro functions in different genera reveals that this proteinase still maintains distinct functions in these genera. In conclusion, a mechanistic understanding of 3C pro will have a potential future impact on antiviral treatment.