DU X, Ding M, Wu Q, Li C H, Guo H, Liu G, Chen Z
Acta Virol. 2020;64(1):59-66. doi: 10.4149/av_2020_108.
Novel duck reovirus (NDRV), the prototype strain of avian orthoreoviruses, continues to circulate among ducks. Analysis of its genome suggested that a putative second open reading frame in the S1 segment encodes a 162-amino acid nonstructural protein with size of 18 kDa, provisionally designated P18. This protein is different from the 17 kDa nonstructural protein encoded in the same open reading frame in other avian orthoreoviruses, which is designated P17 and consists of 146 amino acids. There is no corresponding protein in Muscovy duck reovirus. Antibodies raised to the purified recombinant protein reacted with viral P18 both in vitro and in vivo. In cells, P18 was located predominantly in the nucleus at 6-12 h post-infection, with negligible levels in the cytoplasm. However, the protein accumulated both in the nucleus and cytoplasm at 24 to 36 h post-infection. Immunohistochemistry indicated that P18 strongly accumulates in spleen tissues of infected ducklings. Collectively, the data provide the direct experimental evidence that P18 is expressed by novel duck reovirus both in vivo and in vitro. Keywords: duck reovirus; expression; characterization; novel P18 protein.
新型鸭呼肠孤病毒（NDRV）是禽正呼肠孤病毒的原型毒株，仍在鸭群中传播。对其基因组的分析表明，S1片段中一个假定的第二个开放阅读框编码一种162个氨基酸的非结构蛋白，大小为18 kDa，暂命名为P18。该蛋白与其他禽正呼肠孤病毒同一开放阅读框中编码的17 kDa非结构蛋白不同，后者命名为P17，由146个氨基酸组成。番鸭呼肠孤病毒中没有相应的蛋白。针对纯化重组蛋白产生的抗体在体外和体内均与病毒P18发生反应。在细胞中，感染后6至12小时，P18主要位于细胞核中，细胞质中的水平可忽略不计。然而，在感染后24至36小时，该蛋白在细胞核和细胞质中均有积累。免疫组织化学表明，P18在感染雏鸭的脾脏组织中强烈积累。总体而言，这些数据提供了直接的实验证据，证明P18在体内和体外均由新型鸭呼肠孤病毒表达。关键词：鸭呼肠孤病毒；表达；特性；新型P18蛋白
