Detection of Turnip Yellows Virus-encoded RNA-dependent RNA polymerase using monoclonal antibodies

Abstract

Monoclonal antibodies (MAbs) to the RNA-dependent RNA polymerase (RdRp) of Turnip yellows virus (TuYV, syn. Beet western yellows virus) were obtained using as immunogen the recombinant protein expressed in Escherichia coli. It was demonstrated that the MAbs obtained recognize the C-terminal part of the recombinant viral replicase where the active centre of the enzyme is located. A protein band with a molecular mass of about 70 kDa was revealed by Western blot analysis with total protein extracts from infected oil-seed rape plants, while it was missing in healthy and inoculated virus resistant plants. These results confirm that the full-length TuYV replicase (67 kDa protein), which is proteolytically processed from the P1 + P2, is not further processed during the infection process. Its appearance in infected plant cells is subjected to certain dynamics during the process of the infection. The result presented in this paper is the first successful attempt to detect the RdRp from Luteoviridae in native plant extracts.

Keywords:

• Turnip yellows virus
• RNA-dependent RNA polymerase
• replication
• monoclonal antibodies
• expression

Acknowledgement

This study was possible in part due to the support by grants from Bundesministerium für Bildung und Forschung (Germany), Grant RUS98/168.