RNA Structures Required for Production of Subgenomic Flavivirus RNA
Autor: | Ezequiel Balmori Melian, Hongping Dong, Alexander A. Khromykh, Judy Edmonds, Nadia Floden, Tomoko Nagasaki, Katherine Truong, Shessy Torres, Pei Yong Shi, Anneke Funk |
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Rok vydání: | 2010 |
Předmět: |
Untranslated region
Immunology Microbiology Mice Kunjin virus Virology Exoribonuclease Animals Guide RNA 3' Untranslated Regions Subgenomic mRNA Genetics biology Flavivirus RNA biology.organism_classification Non-coding RNA Genome Replication and Regulation of Viral Gene Expression DNA-Binding Proteins Insect Science Exoribonucleases Nucleic Acid Conformation RNA Viral Pseudoknot West Nile virus |
Zdroj: | Journal of Virology. 84:11407-11417 |
ISSN: | 1098-5514 0022-538X |
Popis: | Flaviviruses are a group of single-stranded, positive-sense RNA viruses causing ∼100 million infections per year. We have recently shown that flaviviruses produce a unique, small, noncoding RNA (∼0.5 kb) derived from the 3′ untranslated region (UTR) of the genomic RNA (gRNA), which is required for flavivirus-induced cytopathicity and pathogenicity (G. P. Pijlman et al., Cell Host Microbe, 4: 579-591, 2008). This RNA (subgenomic flavivirus RNA [sfRNA]) is a product of incomplete degradation of gRNA presumably by the cellular 5′-3′ exoribonuclease XRN1, which stalls on the rigid secondary structure stem-loop II (SL-II) located at the beginning of the 3′ UTR. Mutations or deletions of various secondary structures in the 3′ UTR resulted in the loss of full-length sfRNA (sfRNA1) and production of smaller and less abundant sfRNAs (sfRNA2 and sfRNA3). Here, we investigated in detail the importance of West Nile virus Kunjin (WNV KUN ) 3′ UTR secondary structures as well as tertiary interactions for sfRNA formation. We show that secondary structures SL-IV and dumbbell 1 (DB1) downstream of SL-II are able to prevent further degradation of gRNA when the SL-II structure is deleted, leading to production of sfRNA2 and sfRNA3, respectively. We also show that a number of pseudoknot (PK) interactions, in particular PK1 stabilizing SL-II and PK3 stabilizing DB1, are required for protection of gRNA from nuclease degradation and production of sfRNA. Our results show that PK interactions play a vital role in the production of nuclease-resistant sfRNA, which is essential for viral cytopathicity in cells and pathogenicity in mice. |
Databáze: | OpenAIRE |
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