title: Cooperative enhancement of translation by two adjacent microRNA-122/Argonaute 2 complexes binding to the 5' untranslated region of hepatitis C virus RNA.
abstract: The liver-specific microRNA-122 (miR-122) binds to two conserved binding sites in the 5' UTR of hepatitis C virus (HCV) RNA. This binding was reported to enhance HCV RNA replication, translation and stability. We have analysed binding of miR-122/Argonaute 2 (Ago2) complexes to these sites using anti-Ago2 co-immunoprecipitation of radioactively labelled HCV RNAs along with ectopic miR-122 in HeLa cells. Our results show that the miR-122 target sites can be addressed separately. When both target sites were addressed simultaneously, we observed a synergistic binding of both miR/Ago2 complexes. Consistently, simultaneous binding of both miR-122/Ago2 complexes results in cooperative translation stimulation. In the binding assays as well as in the translation assays, binding site 1 has a stronger effect than binding site 2. We also analysed the overall RNA stability as well as the 5' end integrity of these HCV RNAs in the presence of miR-122. Surprisingly, using short HCV reporter RNAs, we did not find effects of miR-122 binding on overall RNA stability or 5' end integrity over up to 36 h. In contrast, using full-length HCV genomes that are incapable of replication, we found a positive influence of miR-122 on RNA stability, indicating that features of the full-length HCV genome that do not reside in the 5' and 3' UTRs may render HCV RNA genome stability miR-122 dependent.
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Anika
authors.initials: A
authors.lastname: Nieder-Röhrmann
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Nadia
authors.initials: N
authors.lastname: Dünnes
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Gesche K
authors.initials: GK
authors.lastname: Gerresheim
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Lyudmila A
authors.initials: LA
authors.lastname: Shalamova
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Herchenröther
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Niepmann
mesh_terms: D020121:5' Untranslated Regions; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D016679:Genome, Viral; D006367:HeLa Cells; D016174:Hepacivirus / Q000235:genetics / Q000378:metabolism*; D006526:Hepatitis C / Q000378:metabolism* / Q000821:virology*; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000821:virology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D020871:RNA Stability; D012367:RNA, Viral / Q000378:metabolism*
chemical_list: D020121:5' Untranslated Regions; C466422:AGO2 protein, human; D060565:Argonaute Proteins; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D012367:RNA, Viral