School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, SA 5064, Australia. eini
Virus Res. 2012 Jul;167(1):97-101. doi: 10.1016/j.virusres.2012.03.012. Epub 2012 Apr 6.
DNA β satellites are circular single-stranded molecules associated with some monopartite begomoviruses in the family Geminiviridae. They co-infect with their helper viruses to induce severe disease in economically important crops. The βC1 protein encoded by DNA β is a pathogenicity determinant and has been reported to suppress post-transcriptional gene silencing (PTGS). The βC1 proteins from various DNA β molecules show low levels of amino acid sequence conservation. We show here that the βC1 from DNA β associated with Cotton leaf curl Multan virus (CLCuMV) is a suppressor of systemic PTGS. When this DNA β satellite co-inoculated with a heterologous helper virus, Tomato leaf curl virus (ToLCV), reduced the level of ToLCV siRNA and this was associated with a higher level of virus accumulation in infected tobacco plants. This may be a mechanism by which βC1 protects a heterologous virus from host gene silencing.
DNAβ卫星是与双生病毒科中单分体病毒相关的环状单链分子。它们与辅助病毒共同感染，导致经济作物的严重疾病。DNAβ编码的βC1蛋白是一个致病性决定因素，据报道它可以抑制转录后基因沉默（PTGS）。来自不同 DNAβ分子的βC1 蛋白显示出低水平的氨基酸序列保守性。我们在这里表明，与棉花曲叶病毒（CLCuMV）相关的 DNAββC1 是系统性 PTGS 的抑制剂。当这种 DNAβ卫星与异源辅助病毒番茄曲叶病毒（ToLCV）共同接种时，会降低 ToLCV siRNA 的水平，这与感染烟草植物中更高水平的病毒积累有关。这可能是βC1 保护异源病毒免受宿主基因沉默的一种机制。
