FIG 9.
Proposed model of positive NCL regulation of FMDV infection. Following FMDV infection, NCL translocates from the nucleus to the cytoplasm by an as yet incompletely defined mechanism, possibly linked to the proteinase activity of 3Cpro. Once in the cytoplasm, NCL promotes the initiation of FMDV IRES-driven translation by supporting the binding of translation initiation complexes to viral IRES. The promotion of viral IRES-driven translation may also contribute indirectly to the positive effect of NCL on viral RNA synthesis. However, NCL is not involved in FMDV binding or entry.