EXPRESSION OF RECOMBINANT E2-PROTEIN AND C-PROTEIN OF RUBELLA-VIRUS IN INSECT CELLS

We have constructed a recombinant baculovirus expressing the rubella v irus E2 (42-45 KDa) and C (34 KDa) proteins. Sf9 cells infected with r ecombinant virus were able to synthesize and process the two proteins coded by a unique precursor gene. By immunoblot and immunoprecipitatio n analysis with polyclonal and monoclonal antibodies, a precursor poly protein (66 KDa) and two other proteins migrating with an apparent mol ecular weight of 42 KDa and 36KDa were recognized as E2 glycoprotein a nd C protein, respectively. The recombinant E2 protein appeared to be glycosylated since it was susceptible to tunicamycin. The results indi cate that the RV polyprotein coding for E2 and C is expressed and prot eolytically cleaved in insect cells. This baculovirus expression syste m provides a useful alternative approach for the production of rubella virus antigens and should allow the purification of large quantities of the RV proteins for further biochemical and immunological studies.