Mutation analysis of the RNA silencing suppressor NS1 encoded by avian influenza virus H9N2.
Mutation analysis of the RNA silencing suppressor NS1 encoded by avian influenza virus H9N2.
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DOI：
10.1099/vir.0.000095
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发表时间：
2015-07
期刊：
影响因子：
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通讯作者：
X. Jing;Jie Xu;Meina Fan;Lin Ma;Xuyang Huang;Xiaoyun Wang;Shuhong Sun;Changxiang Zhu;Hongmei Liu
中科院分区：
文献类型：
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作者：
X. Jing;Jie Xu;Meina Fan;Lin Ma;Xuyang Huang;Xiaoyun Wang;Shuhong Sun;Changxiang Zhu;Hongmei Liu
非结构蛋白1（NS1）结合小干扰RNA并抑制植物中的RNA沉默，但这种抑制的潜在机制尚不清楚。因此，在这里，我们的特点是NS1编码的禽流感病毒H9N2。NS1蛋白能够抑制由正义RNA或双链RNA（dsRNA）诱导的RNA沉默。利用缺失突变体和点突变体，我们发现NS1的前70个残基可以抑制由正义转基因引发的RNA沉默，但该序列不足以阻断dsRNA诱导的沉默。NS1的两个精氨酸残基（35R和46R）的任何突变（这有助于其同源二聚体结构）导致其沉默抑制活性的丧失。这些结果表明，NS1的残基70后的区域是抑制dsRNA诱导的RNA沉默的活性所必需的，并且NS1的二聚体结构在其RNA沉默抑制功能中起关键作用。
Non-structural protein 1 (NS1) binds small interfering RNA and suppresses RNA silencing in plants, but the underlying mechanism of this suppression is not well understood. Therefore, here we characterized NS1 encoded by the avian influenza virus H9N2. The NS1 protein was able to suppress RNA silencing induced by either sense RNA or double-stranded RNA (dsRNA). Using deletion and point mutants, we discovered that the first 70 residues of NS1 could suppress RNA silencing triggered by sense transgene, but this sequence was not sufficient to block dsRNA-induced silencing. Any mutations of two arginine residues (35R and 46R) of NS1, which contribute to its homodimeric structure, caused the loss of its silencing suppression activity. These results indicate that the region after residue 70 of NS1 is essential for the repression activity on dsRNA-induced RNA silencing, and that the dimeric structure of NS1 plays a critical role in its RNA silencing suppression function.