title: Competitive binding between miR-122 and p68 onto hepatitis C viral RNA.
abstract: BACKGROUND
  Liver-specific microRNA (miR)-122 has been shown to be involved in regulating translation of hepatitis C viral (HCV) RNA. This study aimed to explore the molecular mechanism of miR-122 in regulating HCV RNA translation initiation.
  
  
  METHODS
  In human liver hepatocellular carcinoma cell line HepG2, UV cross-link assay was performed on a large scale to identify RNA-binding proteins with gradient concentrations of miR-122. Analytical ultracentrifugation was then used to separate the translation initiation complexes. All RNA-binding proteins were then identified by Western blotting.
  
  
  RESULTS
  The binding of 68 kDa protein (p68) to HCV RNA was suppressed by the addition of miR-122 via the competitive binding assay. Such inhibition can be eliminated by the addition of 2'-O-methylated oligonucleotides. This binding suppression was determined to be specific for miR-122, which used the mature single-stranded RNA to suppress the binding of p68 onto HCV RNA. This binding inhibition was further validated by using authentic miR-122 with conserved regions and mutated sequences.
  
  
  CONCLUSIONS
  The binding of p68 onto HCV RNA can be specifically inhibited by miR-122 via a competitive binding process.
authors.affiliation: State Key Discipline and Center for Infectious Diseases, Tangdu Hospital Affiliated to the Fourth Military Medical University, Xi'an, Shaanxi, China (mainland).
authors.forename: Fu-Tao
authors.initials: FT
authors.lastname: Zhao
authors.affiliation: State Key Discipline and Center for Infectious Diseases, Tangdu Hospital Affiliated to the Fourth Military Medical University, Xi'an, Shaanxi, China (mainland).
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: State Key Discipline and Center for Infectious Diseases, Tangdu Hospital Affiliated to the Fourth Military Medical University, Xi'an, Shaanxi, China (mainland).
authors.forename: Yong-Xing
authors.initials: YX
authors.lastname: Zhou
authors.affiliation: Department of Infectious Diseases, Wuhan General Hospital of Guangzhou Military Area Command, Wuhan, Hubei, China (mainland).
authors.forename: Qun
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Infectious Diseases, Wuhan General Hospital of Guangzhou Military Area Command, Wuhan, Hubei, China (mainland).
authors.forename: Le
authors.initials: L
authors.lastname: Song
authors.affiliation: Department of Infectious Diseases, Wuhan General Hospital of Guangzhou Military Area Command, Wuhan, Hubei, China (mainland).
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Jiang
authors.affiliation: State Key Discipline and Center for Infectious Diseases, Tangdu Hospital Affiliated to the Fourth Military Medical University, Xi'an, Shaanxi, China (mainland).
authors.forename: Zhan-Sheng
authors.initials: ZS
authors.lastname: Jia
mesh_terms: D020121:5' Untranslated Regions; D001667:Binding, Competitive; D056945:Hep G2 Cells; D016174:Hepacivirus / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D008970:Molecular Weight; D010442:Peptide Chain Initiation, Translational; D011485:Protein Binding; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020121:5' Untranslated Regions; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D012367:RNA, Viral; D016601:RNA-Binding Proteins
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