In vitro Expression Studies of Three Proteins of Iranian Wheat Stripe Virus

The genome of Iranian wheat stripe virus (IWSV), a tentative member of the genus Tenuivirus, is comprised of three ambisense and one negative sense RNA segments. The coat and non-structural proteins encoded by the vcRNA3 and vRNA4 genes, respectively, were efficiently translated in vitro. Translated proteins of vcRNA3 and vRNA4 transcripts were approximately 35000 and 22000 in Mr, respectively, which could be attributed to the corresponding open reading frames (ORFs). The pc4 protein encoded by the IWSV-vcRNA4 was also translated by the same method. Translation product of vcDNA3 transcript gave a band at the approximate position of 37 kDa. The direct translation product of the DNA clone from IWSV-RNA4 gave a band for pc4 similar to that obtained when transcript RNA was used as a messenger. Translation of NS4 and pc4 in viral and viral complementary strands of IWSV RNA4 confirm its ambisense coding strategy.