The SARS-CoV 3a and 7a Protein May Enhance the Induction of IFN-? / 中国生物工程杂志

ABSTRACT

3a and 7a are nonstructural proteins of SARSCoV, which are encoded separately by ORF 3a and ORF 7a in SARSCoV genome. The expression of 3a has been founded in cells infected by virus in vivo or in vitro. Firstly, the pGL3Control vector was reconstructed , the pGL3Enhancer vector deletious of SV40 promoter gene was obtained . Then the IFN? promoter gene was cloned into the pGL3Enhancer vector and pGLIP21, the Luciferase reporter plasmid with IFN? promoter was established. The availability of pGLIP21 was verified by NDV ,the inductor of IFN?, the Luciferase activity was assayed in cells transfected with pGLIP21 by Luminometer. In order to see the function of 3a and 7a protein of SARSCoV,CHO cells expressing 3a or 7a protein were transfected with pGLIP21, the intensity of luciferase activity was analyzed . By analysis, in vitro, 3a and 7a protein of SARSCoV had the similar ability in triggering the expression of Luceferase gene, i.e 3a and 7a protein of SARSCoV could effectively activate the promoter fragment of IFN? gene. This result will help studying the function of 3a and 7a protein and provide a method to study the nosogenesis mechanism of SARSCoV.