Reconstituted vRNPs. Cellular RNA polymerase II drives expression from pcDNA plasmids to produce 5’ capped and 3’ polyadenylated mRNAs that are translated to express the proteins components of the influenza vRNP and NS proteins as described for each experiment. Cellular RNA polymerase I drives expression from pHH21 plasmids to produce unmodified full-length influenza vRNAs. Although influenza contains 8 different vRNA segments to form a complete virus, here one vRNA segment is expressed so that virus is not generated. Bottom panels illustrates WT-NP-FLAG is as functional as WT-NP in reconstituted vRNP assays using GFP-M vRNA template.