Baculovirus-expressed rabies virus M1 protein is not phosphorylated: it forms multiple complexes with expressed rabies N protein

Abstract

The rabies N, M1, M2, and G antigens have been expressed in Spodoptera frugiperda cells from single gene expression vectors or dual gene vectors (N/M1 or M2/G) using the baculovirus system. Although N protein was phosphorylated, no evidence for M1 phosphorylation was obtained. N-M1 complexes were formed in vivo using dual infections or the coexpression vectors, as well as in vitro in mixing experiments. The free or complexed rabies N and M1 proteins reacted with available monoclonal and polyclonal antibodies. By sedimentation analyses the N-M1 complexes were shown to exist in multiple configurations.