Structural and Functional Diversity of Plant Virus 3'-Cap-Independent Translation Enhancers (3'-CITEs)

• Published in: Frontiers in plant science Vol. 8; p. 2047
• Main Authors: Truniger, Verónica, Miras, Manuel, Aranda, Miguel A
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 29.11.2017
• Subjects: 3′-UTR; cap-independent translation; eIF4F; eukaryotic translation initiation factor; Plant Science; plant virus; translation enhancer element; recombination; eIF4F; 3′-UTR; translation enhancer element; 5′–3′ RNA–RNA interaction; cap-independent translation; eukaryotic translation initiation factor; plant virus
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2017.02047

Most of the positive-strand RNA plant viruses lack the 5'-cap and/or the poly(A)-tail that act synergistically to stimulate canonical translation of cellular mRNAs. However, they have RNA elements in the 5'- or 3'-untranslated regions of their RNAs that are required for their cap-independent translation. Cap-independent translation enhancers (CITEs) have been identified in the genomic 3'-end of viruses belonging to the family and the genus . Seven classes of 3'-CITEs have been described to date based on their different RNA structures. They generally control the efficient formation of the translation initiation complex by varying mechanisms. Some 3'-CITEs bind eukaryotic translation initiation factors, others ribosomal subunits, bridging these to the 5'-end by different mechanisms, often long-distance RNA-RNA interactions. As previously proposed and recently found in one case in nature, 3'-CITEs are functionally independent elements that are transferable through recombination between viral genomes, leading to potential advantages for virus multiplication. In this review, the knowledge on 3'-CITEs and their functioning is updated. We also suggest that there is local structural conservation in the regions interacting with eIF4E of 3'-CITEs belonging to different classes.