Fusion of the green fluorescent protein to amino acids 1 to 71 of bovine respiratory syncytial virus glycoprotein G directs the hybrid polypeptide as a class II membrane protein into the envelope of recombinant bovine herpesvirus-1

It was recently shown that the class II membrane glycoprotein G of bovine respiratory syncytial virus (BRSV) is integrated into the envelope of recombinant bovine herpesvirus-1 (BHV-1) virions in the correct orientation. To verify the hypothesis that the membrane anchor of BRSV G might be suitable to target heterologous polypeptides into the membrane of recombinant BHV-1 particles, an open reading frame encoding a fusion protein between amino acids 1 to 71 of the BRSV G glycoprotein and the green fluorescent protein (TMIIGFP) was recombined into the genome of BHV-1. The resulting recombinant BHV-1/eTMIIGFP had growth properties similar to those of wild-type BHV-1. Live-cell analysis of cells infected with BHV-1/eTMIIGFP indicated that the fusion protein localized to the cell surface. Immunoprecipitations and virus neutralization assays using a GFP-specific antiserum proved that TMIIGFP was incorporated as a class II membrane protein into virions.