Japanese encephalitis virus NS1¡ä protein depends on pseudoknot secondary structure and is cleaved by caspase during virus infection and cell apoptosis

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• 作者：Jin Sun ; Yongxin Yu ; Vincent Deubel
• 关键词：Japanese encephalitis virus ; Pseudoknot structure ; NS1 ; NS1&prime ; Caspase ; Apoptosis
• 刊名：Microbes and Infection
• 出版年：2012
• 出版时间：September, 2012
• 年：2012
• 卷：14
• 期：11
• 页码：930-940
• 全文大小：971 K

文摘

Japanese encephalitis virus (JEV) is a flavivirus with a complex life cycle involving mosquito vectors that mainly target birds and pigs, and causes severe encephalitis in children in Asia. Neurotropic flaviviruses of the JEV serogroup have a particular characteristic of expressing a unique nonstructural NS1¡ä protein, which is a prolongation of NS1 at the C terminus by 52 amino acids derived from a pseudoknot-driven-1 translation frameshift. Protein NS1¡ä is associated with virus neuro-invasiveness. In this study, the need of the pseudoknot structure for NS1¡ä synthesis was confirmed. By using a specific antibody against the prolonged peptide, NS1¡ä was found to be absent from the JEV SA14-14-2 vaccine strain, resulting from a single nucleotide silent mutation in the pseudoknot. A partial cleavage of NS1¡ä at a specific site of its C-terminal appendix recognized by caspases and inhibited by caspase inhibitors suggests a unique feature of intracellular NS1¡ä.