RT Journal Article SR Electronic(1) A1 Jing, Xiuli A1 Xu, Jie A1 Fan, Meina A1 Ma, Lin A1 Huang, Xu A1 Wang, Xiaoyun A1 Sun, Shuhong A1 Zhu, Changxiang A1 Liu, HongmeiYR 2015 T1 Mutation analysis of the RNA silencing suppressor NS1 encoded by avian influenza virus H9N2 JF Journal of General Virology, VO 96 IS 7 SP 1613 OP 1618 DO https://doi.org/10.1099/vir.0.000095 PB Microbiology Society, SN 1465-2099, AB 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., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.000095