Arenaviral Protein Expression Vectors
Arenavirus includes Lassa virus. Lassa viral protein expression vectors are based on the Togo/2016/7082 Isolate with the following reference sequences KU961971.1 (GPC & NP) and KU961972.1 (L & Z proteins). 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.
Lassa (LASV) is an enveloped, negative sense, and single stranded RNA virus that is responsible for the dangerous illness among humans called “Lassa fever,” which has a fatality rate of up to 15%. Humans become infected through exposure to food and contaminated items (urines or feces) of Mastomys rats in West Africa. Person-to-person and laboratory transmission (healthcare setting) can also occur. Around 80% of people who are infected exhibit no symptoms. However, once the symptoms accelerate, it results in impairments of liver, spleen, and kidneys. Currently, there is no vaccine to fight against the illness. Each virion contains two single-stranded RNA segments, in which each segment encodes two proteins. The nucleoprotein (NP) encapsulates the viral genome segments, which is essential for both transcription of mRNA and replication of genome segments. The glycoprotein complex (GPC) mediates viral attachment and cell entry. The large (L) protein is an RNA polymerase involved in transcription, replication, and cap-snatching. The Zinc-binding (Z) protein serves as a matrix protein responsible for viral assembly and budding. Additionally, the Z protein negatively regulates viral replication and transcription, which is important for the suppression of viral and host cell translation. LASV enters the host cell via receptor-mediated endocytosis, particularly, by binding to the peripheral membrane at the cell surface called α-dystroglycan (α-DG). As the endosomal pH drops, the LASV glycoprotein complex (GPC) undergoes a conformational shift that enables the dissociation from α-DG and binding to an endosomal receptor, lysosomal-associated membrane protein 1 (LAMP1). Once bounded to LAMP1, the GPC undergoes additional conformational changes that mediate virus–endosomal membrane fusion and enable release of the LASV genome segments into the cytoplasm.