IMMUNOLOGICAL CROSS-REACTIONS AND INTERACTIONS BETWEEN THE DROSOPHILA-MELANOGASTER REF(2)P-PROTEIN AND SIGMA RHABDOVIRUS PROTEINS

The ref(2)P gene is one of the Drosophila melanogaster genes involved in the inhibition of sigma rhabdovirus multiplication. The partial res triction of viral replication varies according to the ref(2)P alleles and virus strains and involves intracellular interactions between para site and host products. We identified the protein encoded by the ref(2 )P gene and produced polyclonal antibodies directed against the whole ref(2)P protein obtained from a recombinant baculovirus and against a part of the protein expressed as a fusion protein. These antibodies we re used to study the interactions with sigma virus proteins by differe nt immunoprecipitation techniques. We showed that the native ref(2)P p rotein shared conformation-dependent common epitopes with the viral st ructural genome-associated N protein. Furthermore, the cellular protei n was found to be associated in complexes with the viral P protein req uired for RNA polymerase activity. The significance of these observati ons in the control of sigma virus multiplication by its host is discus sed.