Expression of potyvirus proteins in insect cells infected with a recombinant baculovirus

Abstract

The N-terminal portion (P1-HC-Pro-P3) of the tobacco vein mottling virus (TVMV) polyprotein was expressed in insect cells and larvae by a recombinant baculovirus. The proteases necessary to process this TVMV polyprotein fragment were active in insect cells, since mature P1, HC-Pro and P3 proteins were detected by specific antisera in Western blots. Antisera to P1, HC-Pro and P3 also recognized polypeptides with apparent M(r) values predicted for the intermediate processing products of the polyprotein fragment. The results of this study indicate that the autocatalytic processing of TVMV HC-Pro from the polyprotein is supported by insect cells. Helper component activity in extracts of cells infected with recombinant baculovirus was not detected by aphid transmission assay.