Recently, we reported that phosphorylation of a specific residue (Ser157) of the P protein of parainfluenza virus 5 (PIV5), a prototypical paramyxovirus, correlates with decreased viral gene expression and cytokine expression in infected cells.
Using parainfluenza virus type 5 (PIV5) as a model we show that phosphorylation of the P protein, which is a key component of the viral RNA polymerase complex, determines whether or not viral transcription and replication becomes repressed at late times after infection.