Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Virology. 2011 Aug 15;417(1):169-78. doi: 10.1016/j.virol.2011.05.012. Epub 2011 Jun 23.
Programmed -1 ribosomal frameshifting (-1 PRF) is one viral translation strategy to express overlapping genes in positive-strand RNA viruses. Red clover necrotic mosaic virus (RCNMV) uses this strategy to express its replicase component protein p88. In this study, we used a cell-free translation system to map cis-acting RNA elements required for -1 PRF. Our results show that a small stem-loop structure adjacent to the cap-independent translation element in the 3' untranslated region (UTR) of RCNMV RNA1 is required for -1 PRF. Site-directed mutagenesis experiments suggested that this stem-loop regulates -1 PRF via base-pairing with complementary sequences in a bulged stem-loop adjacent to the shifty site. The existence of RNA elements responsible for -1 PRF and the cap-independent translation of replicase proteins in the 3' UTR of RNA1 might be important for switching translation to replication and for regulating the ratio of p88 to p27.
-1 核糖体移码（-1 PRF）是一种病毒翻译策略，用于在正链 RNA 病毒中表达重叠基因。三叶草坏死花叶病毒（RCNMV）使用该策略表达其复制酶成分蛋白 p88。在这项研究中，我们使用无细胞翻译系统来绘制 -1 PRF 所需的顺式作用 RNA 元件。我们的结果表明，RCNMV RNA1 的 3'非翻译区（UTR）中紧邻无帽依赖翻译元件的一个小茎环结构是 -1 PRF 所必需的。定点诱变实验表明，该茎环通过与移位位点附近膨出茎环中的互补序列碱基配对来调节 -1 PRF。负责 -1 PRF 和 RNA1 的 3'UTR 中复制酶蛋白无帽依赖翻译的 RNA 元件的存在可能对于将翻译切换到复制以及调节 p88 与 p27 的比例很重要。
