Transactivation of programmed ribosomal frameshifting by a viral protein
| Autor: | Ali Tas, Sawsan Napthine, Yanhua Li, Zhi Sun, Martijn J. van Hemert, Emmely E. Treffers, Brian L. Mark, Peter A. van Veelen, Eric J. Snijder, Ian Brierley, Longchao Zhu, Andrew E. Firth, Susanne Bell, Ying Fang |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Gene Expression Regulation
Viral Transcriptional Activation Viral protein RNA-dependent RNA polymerase Biology Viral Nonstructural Proteins Slippery sequence medicine.disease_cause Ribosome Ribosomal frameshift Cell Line Transactivation Tandem Mass Spectrometry medicine Rosaniline Dyes Animals Humans Porcine respiratory and reproductive syndrome virus Luciferases Gene Genetics Immunoassay Translational frameshift genetic recoding nsp1beta Multidisciplinary Frameshifting Ribosomal translational control Haplorhini digestive system diseases HEK293 Cells PNAS Plus Electrophoresis Polyacrylamide Gel Chromatography Liquid |
| Zdroj: | Proceedings of the National Academy of Sciences, 111(21), E2172-E2181 Proceedings of the National Academy of Sciences |
| Popis: | Programmed −1 ribosomal frameshifting (−1 PRF) is a widely used translational mechanism facilitating the expression of two polypeptides from a single mRNA. Commonly, the ribosome interacts with an mRNA secondary structure that promotes −1 frameshifting on a homopolymeric slippery sequence. Recently, we described an unusual −2 frameshifting (−2 PRF) signal directing efficient expression of a transframe protein [nonstructural protein 2TF (nsp2TF)] of porcine reproductive and respiratory syndrome virus (PRRSV) from an alternative reading frame overlapping the viral replicase gene. Unusually, this arterivirus PRF signal lacks an obvious stimulatory RNA secondary structure, but as confirmed here, can also direct the occurrence of −1 PRF, yielding a third, truncated nsp2 variant named “nsp2N.” Remarkably, we now show that both −2 and −1 PRF are transactivated by a protein factor, specifically a PRRSV replicase subunit (nsp1β). Embedded in nsp1β’s papain-like autoproteinase domain, we identified a highly conserved, putative RNA-binding motif that is critical for PRF transactivation. The minimal RNA sequence required for PRF was mapped within a 34-nt region that includes the slippery sequence and a downstream conserved CCCANCUCC motif. Interaction of nsp1β with the PRF signal was demonstrated in pull-down assays. These studies demonstrate for the first time, to our knowledge, that a protein can function as a transactivator of ribosomal frameshifting. The newly identified frameshifting determinants provide potential antiviral targets for arterivirus disease control and prevention. Moreover, protein-induced transactivation of frameshifting may be a widely used mechanism, potentially including previously undiscovered viral strategies to regulate viral gene expression and/or modulate host cell translation upon infection. |
| Databáze: | OpenAIRE |
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