Cap-Independent Translation Mechanism of Red Clover Necrotic Mosaic Virus RNA2 Differs from That of RNA1 and Is Linked to RNA Replication

• DOI: 10.1128/jvi.80.8.3781-3791.2006
• Publication Date: 2006-03-29T20:47:35Z
• Authors: Hiroyuki Mizumoto; Hiro-oki Iwakawa; Masanori Kaido; Kazuyuki Mise; Tetsuro Okuno
• Keywords: RNA Caps; 0301 basic medicine; 03 medical and health sciences; Base Sequence; Protein Biosynthesis; Tombusviridae; RNA, Viral; Trifolium; Genome, Viral; 3. Good health

The genome of Red clover necrotic mosaic virus (RCNMV) in the genus Dianthovirus is divided into two RNA molecules RNA1 and RNA2, which have no cap structure at 5' end poly(A) tail 3' end. untranslated region (3' UTR) RCNMV contains an essential element (3'TE-DR1), required for cap-independent translation. In this study, we investigated a translational mechanism RNA2 using firefly luciferase (Luc) gene expression assay system cowpea protoplasts cell-free lysate (BYL) prepared from evacuolated tobacco BY2 protoplasts. We were unable to detect cis-acting sequences that can replace function structure, such as 3'TE-DR1 RNA1. However, uncapped reporter RNA2-Luc, Luc open reading frame (ORF) was inserted between UTR movement protein ORF, effectively translated presence p27 p88 RNA2-Luc replicated. Time course experiments showed activity did not reflect amount RNA2. Mutations replication elements abolished suggesting coupled replication. Our results show differs segmented genomic RNAs RCNMV. present model only generated de novo through viral machinery functions mRNA