Translational control by the La antigen. Structure requirements for rescue of the double-stranded RNA-mediated inhibition of protein synthesis
| Autor: | Ian W. Jeffrey, Michael J. Clemens, José Thijssen, Ger J. M. Pruijn, Marion C. James |
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| Rok vydání: | 1999 |
| Předmět: |
Reticulocytes
viruses Recombinant Fusion Proteins RNA-binding protein Biology Biochemistry Autoantigens eIF-2 Kinase Gene expression Protein biosynthesis Animals RNA Messenger Protein kinase A RNA Double-Stranded Sequence Deletion EIF-2 kinase Cell-Free System fungi RNA RNA-Binding Proteins Bio-Molecular Chemistry Molecular biology Protein kinase R RNA silencing Gene Expression Regulation Ribonucleoproteins Protein Biosynthesis biology.protein Rabbits |
| Zdroj: | European Journal of Biochemistry, 266, 1, pp. 151-62 European Journal of Biochemistry, 266, 151-62 |
| ISSN: | 0014-2956 |
| Popis: | Contains fulltext : 184894.pdf (Publisher’s version ) (Closed access) The La antigen is a protein which can bind both single-stranded and double-stranded forms of RNA and has regulatory effects on gene expression at the levels of transcription and translation. It was previously shown to inhibit the activation of the dsRNA-dependent protein kinase PKR by sequestering and/or unwinding double-stranded RNA. Here, we demonstrate that, as predicted by these properties, the La antigen can rescue protein synthesis in the reticulocyte lysate system from inhibition by low concentrations of dsRNA. This effect is reversed by higher concentrations of dsRNA. Using a series of deletion mutants we have investigated the structural features of the La antigen that are required for these effects. The ability to bind dsRNA is influenced by regions within both the previously characterized N-terminal RNP motif and the C-terminal half of the protein. La mutants with either N-terminal or C-terminal deletions retain the ability to inhibit the protein kinase activity of PKR and to rescue protein synthesis from inhibition by dsRNA. It is notable that sequences in the C-terminal half of the La antigen, including a phosphorylation site at Ser366, which are needed for other regulatory effects of the protein on gene expression are dispensable for the effects of La on PKR. We suggest that La regulates PKR activity solely as a result of its ability to act as an RNA-binding protein that can compete with PKR for limiting amounts of dsRNA. |
| Databáze: | OpenAIRE |
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