Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200025, China.
Microbes Infect. 2012 Sep;14(11):930-40. doi: 10.1016/j.micinf.2012.03.007. Epub 2012 Mar 28.
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' 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' is associated with virus neuro-invasiveness. In this study, the need of the pseudoknot structure for NS1' synthesis was confirmed. By using a specific antibody against the prolonged peptide, NS1' 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' at a specific site of its C-terminal appendix recognized by caspases and inhibited by caspase inhibitors suggests a unique feature of intracellular NS1'.
日本脑炎病毒（JEV）是一种黄病毒，具有复杂的生命周期，涉及以鸟类和猪为主要目标的蚊子媒介，在亚洲可导致儿童严重脑炎。JEV 血清群的神经亲和性黄病毒的一个特殊特征是表达一种独特的非结构 NS1'蛋白，它是 NS1 在 C 末端通过源自假结驱动的 1 翻译移码的 52 个氨基酸延长。蛋白 NS1'与病毒的神经侵袭性有关。在这项研究中，证实了假结结构对 NS1'合成的必要性。通过使用针对延长肽的特异性抗体，发现 JEV SA14-14-2 疫苗株中不存在 NS1'，这是由于假结中的单个核苷酸沉默突变。在其被半胱天冬酶识别的 C 末端附录的特定位点的部分切割以及半胱天冬酶抑制剂的抑制提示了细胞内 NS1'的独特特征。
