Togavirus Protein Expression Vectors

Product Description

Togaviridea Protein Expression Vectors

Togaviruses include Chikungunya (CHIKV) and Semliki Forest (SFV) viruses. The Chikungunya viral protein expression vectors are based on the Chikungunya virus strain 119067 (Genebank: KY057363.1). Semliki Forest viral protein expression vectors are based on the Semliki virus strain NIV8913590 (Genebank: MH426977.1). All of the expression vectors are codon optimized for mammalian cell expression. Choose to add a GFP or his tag to the C terminal end of any protein. A CMV promoter is used for mammalian cell expression and the backbone contains a selection marker for Geneticin (G418). All non-tagged glycoprotein expression vectors have been functionally validated using pseudotyped viral particles. 

Background:

Togaviridae is a family of enveloped RNA viruses transmitted by Aedes mosquitoes, particularly A. aegypti and A. albopictus, which are found mostly in Africa and Asia. They are responsible for various human and animal diseases, including Chikungunya and Semliki Forest virus infections. While Semliki Forest virus infection can cause serious symptoms such as encephalitis, myalgia, and arthralgia, Chikungunya virus infection is often misdiagnosed with Dengue and Zika because it has similar symptoms which include fever, severe joint/muscle pain, headache, nausea, fatigue, and rash. 

Togaviruses are single-stranded positive-sense RNA viruses that produce two polyproteins that are processed into 9 individual viral proteins. Mature virions consist of five structural proteins, the capsid protein (C), the envelope proteins E1, E2, and E3, and the small 6K protein. The four non-structural (NS) proteins including NS1-4 play important roles in viral replication and assembly. The E1 protein contains a hydrophobic fusion peptide and is necessary for viral and cellular membrane fusion. The E2 protein is responsible for receptor binding and is synthesized as the precursor p62, which contains covalently bound E3. Together, the E1 and E2 proteins form heterodimeric spikes on the virion surface. Togaviruses enter the host cell via receptor-mediated endocytosis. The low-pH environment in the endosome induces a conformational change in glycoproteins, specifically the dissociation of the E2/E1 heterodimers followed by E1 trimerization. This results in membrane fusion, causing the release of viral RNA into the cytoplasm for replication and translation.