Centre for Infectious Disease Research, School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
J Virol. 2010 Feb;84(3):1641-7. doi: 10.1128/JVI.01979-09. Epub 2009 Nov 11.
Flavivirus NS1 is a nonstructural protein involved in virus replication and regulation of the innate immune response. Interestingly, a larger NS1-related protein, NS1', is often detected during infection with the members of the Japanese encephalitis virus serogroup of flaviviruses. However, how NS1' is made and what role it performs in the viral life cycle have not been determined. Here we provide experimental evidence that NS1' is the product of a -1 ribosomal frameshift event that occurs at a conserved slippery heptanucleotide motif located near the beginning of the NS2A gene and is stimulated by a downstream RNA pseudoknot structure. Using site-directed mutagenesis of these sequence elements in an infectious clone of the Kunjin subtype of West Nile virus, we demonstrate that NS1' plays a role in viral neuroinvasiveness.
黄病毒 NS1 是一种非结构蛋白，参与病毒复制和固有免疫反应的调节。有趣的是，在感染日本脑炎病毒血清群黄病毒时，通常会检测到一种较大的 NS1 相关蛋白 NS1'。然而，NS1' 是如何产生的，以及它在病毒生命周期中扮演什么角色，尚未确定。在这里，我们提供实验证据表明 NS1' 是核糖体 -1 移码事件的产物，该事件发生在 NS2A 基因起始附近的保守滑链七核苷酸基序处，并受下游 RNA 假结结构的刺激。我们使用西尼罗河病毒 Kunjin 亚型的感染性克隆中的这些序列元件的定点突变，证明 NS1' 在病毒神经侵袭性中发挥作用。
