A new plant protein interacts with eIF3 and 60S to enhance virus-activated translation re-initiation
The plant viral re‐initiation factor transactivator viroplasmin (TAV) activates translation of polycistronic mRNA by a re‐initiation mechanism involving translation initiation factor 3 (eIF3) and the 60S ribosomal subunit (60S). QJ;Here, we report a new plant factor—re‐initiation supporting protein...
Saved in:
Published in | The EMBO journal Vol. 28; no. 20; pp. 3171 - 3184 |
---|---|
Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester, UK
John Wiley & Sons, Ltd
21.10.2009
Blackwell Publishing Ltd EMBO Press Nature Publishing Group |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The plant viral re‐initiation factor transactivator viroplasmin (TAV) activates translation of polycistronic mRNA by a re‐initiation mechanism involving translation initiation factor 3 (eIF3) and the 60S ribosomal subunit (60S). QJ;Here, we report a new plant factor—re‐initiation supporting protein (RISP)—that enhances TAV function in re‐initiation. RISP interacts physically with TAV in vitro and in vivo. Mutants defective in interaction are less active, or inactive, in transactivation and viral amplification. RISP alone can serve as a scaffold protein, which is able to interact with eIF3 subunits a/c and 60S, apparently through the C‐terminus of ribosomal protein L24. RISP pre‐bound to eIF3 binds 40S, suggesting that RISP enters the translational machinery at the 43S formation step. RISP, TAV and 60S co‐localize in epidermal cells of infected plants, and eIF3–TAV–RISP–L24 complex formation can be shown in vitro. These results suggest that RISP and TAV bridge interactions between eIF3‐bound 40S and L24 of 60S after translation termination to ensure 60S recruitment during repetitive initiation events on polycistronic mRNA; RISP can thus be considered as a new component of the cell translation machinery. |
---|---|
Bibliography: | ark:/67375/WNG-PFKVLWBF-4 Supplementary Figure 1SSupplementary Figure 2SSupplementary Figure 3SSupplementary Figure 4SSupplementary Figure LegendsSupplementary Materials and MethodsReview Process File istex:43F124E01C00442CBB6315EEF5BC46112DF6769A ArticleID:EMBJ2009256 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 PMCID: PMC2771092 Present address: Department of Molecular Biology, Umeå University, S-901 87 Umeå, Sweden Present address: Botany Department, Basel University, Plant Health Unit, CH-4056 Basel, Schönbeinstr 6, Switzerland |
ISSN: | 0261-4189 1460-2075 |
DOI: | 10.1038/emboj.2009.256 |