Protein kinase R (EIF2AK2) is activated during viral infection by binding to dsRNA, followed by subsequent dimerization and autophosphorylation. It is also activated by interferon-induced ISGylation. PKR activation leads to a general shutdown of both host and viral protein translation through phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 (EIF2S1/eIF-2-alpha). hRSV nucleoprotein N binds PKR, decreasing EIF2S1 phosphorylation and reactivating translation of viral proteins despite interferon signaling (Groskreutz et al, 2010).