title: Mutation analysis of the RNA silencing suppressor NS1 encoded by avian influenza virus H9N2.
abstract: 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.
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China 2Institute of Immunology, Taishan Medical University, Tai'an, Shandong, PR China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Jing
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Meina
authors.initials: M
authors.lastname: Fan
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Huang
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Wang
authors.affiliation: 3College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Shuhong
authors.initials: S
authors.lastname: Sun
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Changxiang
authors.initials: C
authors.lastname: Zhu
authors.affiliation: 1State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, PR China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D002645:Chickens; D004252:DNA Mutational Analysis; D005786:Gene Expression Regulation; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics / Q000276:immunology* / Q000502:physiology*; D005585:Influenza in Birds / Q000821:virology; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D017384:Sequence Deletion; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C085820:INS1 protein, influenza virus; D050505:Mutant Proteins; D034741:RNA, Small Interfering; D017361:Viral Nonstructural Proteins