Expression of coat protein and non-structural protein of Iranian wheat stripe virus in Escherichia coli

Iranian wheat stripe virus (IWSV) is a tentative member of the genus Tenuivirus. The coat and nonstructural proteins (CP and NS4, respectively) are the most common proteins of tenuiviruses encoded by the vcRNA3 and vRNA4 segments, respectively. The specific antibodies against those proteins can be used for detection of the viruses and investigation of functions of the related genes. To express CP and NS4 of IWSV, the related genes were amplified using specific primers and cloned into the expression vector pET 28a. Recombinant plasmids were used to transform Escherichia coli strain BL21(DE3). The transformed bacteria were cultured in IPTG-induced media. SDS-polyacrylamide gelelectrophoresis showed two bands with molecular weights 40.9 and 23 kDa which corresponded to the molecular weight of the putative products of the related genes in tenuiviruses. The expression of target proteins was confirmed using specific polyclonal antibodies by western blot analysis. The large-scale production of highly purified proteins by a microbial system represents pure antigen free from the contaminating plant materials that can be used to produce the related antibodies.