Long-range RNA-RNA interaction between the 5' nontranslated region and the core-coding sequences of hepatitis C virus modulates the IRES-dependent translation.
Hepatitis C virus (HCV) is a positive-sense RNA virus approximately 9600 bases long. An internal ribosomal entry site (IRES) spans the 5' nontranslated region, which is the most conserved and highly structured region of the HCV genome. In this study, we demonstrate that nucleotides 428-442 of the HCV core-coding sequence anneal to nucleotides 24-38 of the 5'NTR, and that this RNA-RNA interaction modulates IRES-dependent translation in rabbit reticulocyte lysate and in HepG2 cells. The inclusion of the core-coding sequence (nucleotides 428-442) significantly suppressed the translational efficiency directed by HCV IRES in dicistronic reporter systems, and this suppression was relieved by site-directed mutations that blocked the long-range interaction between nucleotides 24-38 and 428-442. These findings suggest that the long-range interaction between the HCV 5'NTR and the core-coding nucleotide sequence down-regulate cap-independent translation via HCV IRES. The modulation of protein synthesis by long-range RNA-RNA interaction may play a role in the regulation of viral gene expression.
Kim
Yoon Ki
YK
Department of Life Science, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Korea.
Lee
Song Hee
SH
Kim
Chon Saeng
CS
Seol
Su Kyoung
SK
Jang
Sung Key
SK
D020121:5' Untranslated Regions; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D017124:Conserved Sequence; D016174:Hepacivirus / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D020121:5' Untranslated Regions; D012367:RNA, Viral