Prokaryotic Expression and Immuno-localization of Replication Protein Gene of Tobacco curly shoot virus
烟草曲茎病毒复制蛋白基因的原核表达和免疫定位

The replication protein (Rep) gene of Tobacco curly shoot virus (TbCSV) Y35 isolate was obtained from the infected tobacco plants by PCR and cloned into expression vector pGEX-4T-1 to generate the recombinant plasmid pGEX-Y35Rep. The recombinant plasmid was introduced into Escherichia coli strain BL21(DE3) pLys S, and TbCSV Rep fusion protein was expressed with induction by IPTG and some products were soluble. The Rep fusion protein was purified with GST-Sepharose 4B affinity chromatography and its polyclonal antibody was produced in a rabbit. Studies on subcellular distribution of TbCSV Rep protein in infected tobacco leaves revealed that Rep protein mainly exists in the fractions containing the nucleus. Immuno-gold labeling with the antibody against Rep fusion protein also indicated that Rep protein localized in the nuclei of infected tobacco cells.