Fig 3.

Phosphorylated Y132 of M1 is essential for virus rescue. A 12-plasmid reverse genetic system was used to rescue recombinant viruses with WT and mutated M1s (Y132A/F/D). (A) At 72 h p.t., the culture supernatants were harvested and subjected to plaque assays on MDCK cells. All recombinant viruses containing M1 mutants failed to be rescued. (B) At 72 h p.t., the transfected cells were lysed for Western blot analysis. HA, NP, and M1 were detected with respective antibodies. β-Actin was probed as a loading control. Blank, cells transfected without an added M1 plasmid.