虫媒黄病毒亚基因组RNA

Arthropod-borne flavivirus subgenomic RNA

黄病毒是一大科人类致病性的单股正链RNA病毒。黄病毒包括登革病毒、西尼罗脑炎病毒及日本脑炎病毒等成员,主要径通过节肢动物的叮咬进行传播,即为虫媒黄病毒。研究发现,在虫媒黄病毒复制过程中,除病毒基因组正链RNA、互补的负链RNA及两者的杂合RNA分子外,在病毒感染细胞后还能产生一种病毒亚基因组RNA(subgenomic RNA,sgRNA)。近年对这种sgRNA展开了比较多的研究,结果表明,其产生机制与已知的其他病毒sgRNA产生机制并不相同。该sgRNA的产生与虫媒黄病毒基因组3’非编码区所形成的保守二级结构有关,同时宿主核酸酶对其的不完全降解亦有重要作用。虫媒黄病毒基因组3’非编码区中带有多个与病毒复制相关的RNA元件,而sgRNA的发现有助于全面地认识病毒RNA与宿主RNA代谢途径间的相互作用,为最终阐明病毒的致病机制奠定基础。

Flavivirus is an enormous family of human pathogenic single-strand RNA virus.Some members of genus flavivirus,which includes dengue,Japanese encephalitis and West Nile viruses,are designated as Arthropod-borne Flavivirus.During viral replication,it is generally accepted that besides viral genomic RNA,its complementary negative RNA and the hybrid RNAs of both are generated.At the same time,some studies suggested that a set of small sub-genomic viral RNAs （sgRNAs） were also produced in Arthropod-borne flaviviruses infected host cells.Unlike the other RNA viruses,the mechanism of sgRNA genera- tion by Arthropod-borne Flavivirus were due to conserved RNA secondary structures formed by viral 3’NCR,moreover incom- plete degradation by host mRNA exo-nuclease was also involved.Given that viral 3’NCR contained several replication associ- ated cis-RNA elements.The discovery of the sgRNA might properly changed our view of viral pathogenicity,and help us to better understand interaction between RNA virus and host RNA metabolism.