Binding of tobamovirus replication protein with small RNA duplexes.
The sequence profiles of small interfering RNAs (siRNAs) in Arabidopsis infected with the crucifer tobamovirus tobacco mosaic virus (TMV)-Cg were determined by using a small RNA cloning technique. The majority of TMV-derived siRNAs were 21 nt in length. The size of the most abundant endogenous small RNAs in TMV-infected plants was 21 nt, whilst in mock-inoculated plants, it was 24 nt. Northern blot analysis revealed that some microRNAs (miRNAs) accumulated more in TMV-infected plants than in mock-inoculated plants. The question of whether the TMV-Cg-encoded 126K replication protein, an RNA-silencing suppressor, caused small RNA enrichment was examined. Transient expression of the replication protein did not change the pattern of miRNA processing. However, miRNA, miRNA* (the opposite strand of the miRNA duplex) and hairpin-derived siRNA all co-immunoprecipitated with the replication protein. Gel mobility-shift assays indicated that the replication protein binds small RNA duplexes. These results suggest that the tobamovirus replication protein functions as a silencing suppressor by binding small RNA duplexes, changing the small RNA profile in infected plants.
Kurihara
Yukio
Y
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Inaba
Naoko
N
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Kutsuna
Natsumaro
N
Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
Takeda
Atsushi
A
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Tagami
Yuko
Y
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Watanabe
Yuichiro
Y
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
D017360:Arabidopsis / Q000378:metabolism* / Q000821:virology*; D003593:Cytoplasm / Q000378:metabolism; D035683:MicroRNAs / Q000737:chemistry / Q000378:metabolism*; D008970:Molecular Weight; D018515:Plant Leaves / Q000378:metabolism / Q000821:virology; D011485:Protein Binding; D018749:RNA, Plant / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*; D034743:RNA-Induced Silencing Complex / Q000378:metabolism; D014027:Tobacco Mosaic Virus / Q000737:chemistry*; D014764:Viral Proteins / Q000378:metabolism*
D035683:MicroRNAs; D018749:RNA, Plant; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex; D014764:Viral Proteins