Liu Huijun, Wei Chunhong, Zhong Yongwang, Li Yi
Peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
FEBS Lett. 2007 May 29;581(13):2534-40. doi: 10.1016/j.febslet.2007.04.071. Epub 2007 May 4.
Virus-encoding nuclear transcriptional regulators play important roles in the viral life cycle. Most of these proteins exhibit intrinsic transcriptional activation or repression activity, and are involved in the regulation of the expression of virus genome itself or important cellular genes to facilitate viral replication and inhibit antiviral responses. Here, we report that the minor core protein P8 of Rice black-streaked dwarf virus, a dsRNA virus infecting host plants and insects, is targeted to the nucleus of insect and plant cells via its N-terminal 1-40 amino acids and possesses potent active transcriptional repression activity in Bright Yellow-2 tobacco suspension cells. Moreover, P8, like many transcriptional regulatory proteins, is capable of forming homo-dimers within insect cells and in vitro. All these data suggest that P8 is likely to enter the nucleus of host cell and play an important role as a negative transcriptional regulator of host gene expression during the process of virus-host interaction.
病毒编码的核转录调节因子在病毒生命周期中发挥重要作用。这些蛋白质大多具有内在的转录激活或抑制活性，参与病毒基因组本身或重要细胞基因表达的调控，以促进病毒复制并抑制抗病毒反应。在此，我们报道了水稻黑条矮缩病毒的次要核心蛋白P8，这是一种感染宿主植物和昆虫的双链RNA病毒，它通过其N端的1 - 40个氨基酸靶向昆虫和植物细胞的细胞核，并在亮黄-2烟草悬浮细胞中具有强大的活性转录抑制活性。此外，与许多转录调节蛋白一样，P8能够在昆虫细胞内和体外形成同型二聚体。所有这些数据表明，P8可能进入宿主细胞核，并在病毒 - 宿主相互作用过程中作为宿主基因表达的负转录调节因子发挥重要作用。
