2A Protease Is Not a Prerequisite for Poliovirus Replication

the strains ranked as OME2A < OME PV1(M)OM. These results suggest that 2A pro is not essential for full-length dc PV to form progeny virus and that it contributes to the efficient viral replication and/or induction of a CPE. To clarify whether 2A pro is essential for P1-null (lacking the entire coding sequence for capsid proteins) PV, the RNA replication activity of P1-null PV (pOMP1) or P1-null PV without 2A pro (pOMP12A) or without both 2A pro and 2B (pOMP12A2B) was examined. The RNAs of pOMP1 and pOMP12A could replicate and form progeny viruses under a trans supply of P1 protein, whereas the RNA of pOMP12A2B could not. These results suggest that 2A pro is not needed for the replication of P1-null PV, although it is important for PV RNA replication and inducing a CPE. To know whether a 2A pro -deficient PV can be used as a vector, a P1-null PV containing the enhanced green fluorescent protein (EGFP) coding sequence with or without 2A pro was examined. It expressed fluorescent protein. This result suggests that 2A pro -deficient PV can express foreign genes.