analysis of the tomato spotted wilt virus ambisense s rna-encoded hairpin structure in translation番茄的分析发现必双义的病毒rna编码发夹结构在翻译.pdfVIP

Analysis of the Tomato spotted wilt virus Ambisense S RNA-Encoded Hairpin Structure in Translation Christina Geerts-Dimitriadou, Yun-Yueh Lu, Corinne Geertsema, Rob Goldbach{, Richard Kormelink* Laboratory of Virology, Wageningen University, Wageningen, The Netherlands Abstract Background: The intergenic region (IR) of ambisense RNA segments from animal- and plant-infecting (-)RNA viruses functions as a bidirectional transcription terminator. The IR sequence of the Tomato spotted wilt virus (TSWV) ambisense S RNA contains stretches that are highly rich in A-residues and U-residues and is predicted to fold into a stable hairpin structure. The presence of this hairpin structure sequence in the 39 untranslated region (UTR) of TSWV mRNAs implies a possible role in translation. Methodology/Principal Findings: To analyse the role of the predicted hairpin structure in translation, various Renilla luciferase constructs containing modified 39 and/or 59 UTR sequences of the TSWV S RNA encoded nucleocapsid (N) gene were analyzed for expression. While good luciferase expression levels were obtained from constructs containing the 5 9 UTR and the 39 UTR, luciferase expression was lost when the hairpin structure sequence was removed from the 39 UTR. Constructs that only lacked the 59 UTR, still rendered good expression levels. When in addition the entire 39 UTR was exchanged for that of the S RNA encoded non-structural (NSs) gene transcript, containing the complementary hairpin folding sequence, the loss of luciferase expression could only be recovered by providing the 5 9 UTR sequence of the NSs transcript. Luciferase activity remained unaltered when the hairpin structure sequence was swapped for the analogous one from Tomato yellow ring virus, another distinct tospovir