Characterization of human parainfluenza virus type 2 RNAs in infected cells and by in vitro synthesis

The RNA species synthesized in HPIV-2 infected CV-1 cells were identified and characterized. The largest RNA of approximately 5.5 × 106 in molecular weight (MW) based on electrophoretic mobility, was identified as the genomic RNA. The other small RNA species of MWs 2.4 × 106, 1.1 × 106, 0.77 × 106, 0.68 × 106 and 0.5 × 106 were identified as mRNAs. The five smallest RNAs were also synthesized in vitro and comigrated with RNAs synthesized in virus-infected cells. mRNAs synthesized both in vitro and in virus-infected cells were translated in vitro. NP, P, M and V proteins synthesized in vitro comigrated, when analyzed by SDS-PAGE, with the authentic proteins synthesized in virus-infected cells. Additionally, peptide mapping showed that the NP, P and M proteins synthesized in vitro were indistinguishable from their counterparts synthesized in infected cells. Analysis of the proteins from virions identified L, HN, NP, F (F1, F2), P, M and V proteins as virion structural proteins. Electrophoretic mobility of reduced and nonreduced F proteins was found to be different due to the conformational changes conferred by disulfide bonds.