Cloning and Sequence Analysis of Envelope Glycoprotein E1 Gene of Rubella Virus, JR23 Strain

Rubella virus (RV), the only member of the Rubivirusgenus in the family Togaviridae, is a single stranded, pos itive sense RNA virus. The structural gene in the 3′endof the genomic RNA encodes 3 virion proteins: the capsidprotein (C), and two envelop glycoproteins, E1 and E2.E1 gene is 1484 bp in length, encoding the hemagglutina tion activity and immune antigenic sites of RV. Studies in dicate that the degrees of variance in E1 gene sequence aresimilar to that of the complete gen…

Cloning and Sequence Analysis of Envelope Glycoprotein E1 Gene of Rubella Virus, JR23 Strain

To construct an expression vector containing the E1 glycoprotein gene of rubella virus for the study on the effect of mutation of the E1 gene glycoprotein and the analysis of phylogenetic differences of sequences, the gene encoding the E1 envelope glycoprotein was amplified from rubella virus, Jinan strain JR23, by RT-PCR and ligated into PMD-18T vector. The clones that carried the E1 gene were identified after amp r selection and analysis of restriction enzyme digestion. After sequencing this gene was analyzed by Danstar and Winstar programs, and the map of phylogenetic tree was drawn. The clone of E1 glycoprotein was thus constructed. It was found that the sequence differences between JR23 strain and the TCRB strain from Japan and those between JR23 strain and Thomas strain of England were rather small with difference values of 0.9% and 1.2% respectively. Yet those between JR23 strain and BRD2 strain from Beijing and those between JR23 strain and XG379 strain from Hong Kong were comparatively larger with difference values of 7.6% and 7.3% respectively. The sequence of JR23 strain with other strains was less than 3% except the NC strain (3.7%). It concludes that the construction of E1 glycoprotein gene offers an approach to study the relationship between structures and functions of E1 gene and its gene products. In the phylogenetic tree, it shows that there are significant differences in the sequences of rubella virus isolated in China, and this might be helpful to develop an effective subunit vaccine.