Figure 2.

Poliovirus capsid protein VP0 contains an LC3A-like epitope. (A) HeLa cells were infected with poliovirus at an MOI of 10 and the samples were collected at the indicated times post-infection. Mock-infected sample is collected at 6 h. Western blot was developed with a rabbit monoclonal anti-LC3A antibody (Cell Signaling). LC3A * designates abnormal higher molecular weight LC3A signals. (B) HeLa cells were transfected with either full-length poliovirus RNA (V) or replicon RNA (R) coding for only P2P3 replication proteins and developed with the same anti-LC3A antibody as in A (upper panel). Staining with anti-polio 2C antibody shows polio replication (middle panel). Actin is shown as a loading control (lower panel). (C) Proteins from poliovirus virions purified through CsCl₄ gradient were resolved on an SDS-PAGE gel and either subjected to a Western blotting with the anti-LC3A antibody (left), or visualized with a Coomassie stain (right). (D) Top—amino-acid sequences of the VP4/VP2 cleavage site in VP0 and the alanine substitutions in the 12A mutant. HeLa cells were transfected with either wt polio RNA or the RNA with 12A substitution and the cell lysates were subject to Western blots with either anti-LC3A (top panel) or anti-polio 2C antibodies (bottom panel).