Okamoto Kimiyuki, Nagano Hideaki, Iwakawa Hirooki, Mizumoto Hiroyuki, Takeda Atsushi, Kaido Masanori, Mise Kazuyuki, Okuno Tetsuro
Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Virology. 2008 May 25;375(1):205-12. doi: 10.1016/j.virol.2008.02.004. Epub 2008 Mar 4.
The genome of Red clover necrotic mosaic virus (RCNMV) consists of RNA1 and RNA2. RNA1 encodes N-terminally overlapping replication proteins, p27 and p88, which are translated in a cap-independent manner. The 3' untranslated region of RNA1 contains RNA elements essential for cap-independent translation and negative-strand RNA synthesis. In this study, we investigated how p27 and p88 were engaged in the replication of RCNMV genomic RNAs by using DNA vectors or in vitro transcribed RNAs in protoplasts and in a cell-free extract of evacuolated BY-2 protoplasts. Our results show a cis-preferential requirement of p88, but not of p27, for the replication of RNA1. This mechanism might help to facilitate a switch in the role of RNA1 from mRNA to a replication template.
红三叶草坏死花叶病毒（RCNMV）的基因组由RNA1和RNA2组成。RNA1编码N端重叠的复制蛋白p27和p88，它们以不依赖帽子的方式进行翻译。RNA1的3'非翻译区包含不依赖帽子翻译和负链RNA合成所必需的RNA元件。在本研究中，我们通过在原生质体以及经抽空处理的BY-2原生质体的无细胞提取物中使用DNA载体或体外转录的RNA，研究了p27和p88如何参与RCNMV基因组RNA的复制。我们的结果表明，RNA1的复制对p88有顺式优先需求，而对p27没有。这种机制可能有助于促进RNA1的作用从信使RNA转变为复制模板。
