The La protein from human liver cells interacts specifically with the U-rich region in the hepatitis C virus 3' untranslated region

J Hum Virol. Sep-Oct 1999;2(5):296-307.


Objective: To identify cellular factors in human liver that interact with hepatitis C virus (HCV) 5' and 3' untranslated regions (UTRs) and therefore possibly are involved in the regulation of HCV transcription or translation.

Methods: We prepared cytoplasmic extracts from human liver biopsy samples and fractionated cellular factors on ion exchange columns. The various fractions from ion exchange columns were subjected to ultraviolet (UV) cross-linking with radiolabeled HCV 5' and 3' UTR RNA probes.

Results: Two major 45- and 46-kd proteins that interacted specifically with the HCV 5' and 3' UTR were identified. Using Western blot and immunoprecipitation, these proteins were identified as the La antigen.

Conclusion: Our results demonstrate that the La protein from human liver biopsy cells interacts specifically with the U-rich region in the positive strand of the HCV 3' UTR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / metabolism*
  • 5' Untranslated Regions / metabolism*
  • Autoantigens / genetics
  • Autoantigens / metabolism*
  • Binding, Competitive
  • Blotting, Western
  • Cells, Cultured
  • Cross-Linking Reagents
  • Hepacivirus / metabolism*
  • Humans
  • Liver / metabolism*
  • Precipitin Tests
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / isolation & purification
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism*
  • Transcription Factors / metabolism*
  • Ultraviolet Rays


  • 3' Untranslated Regions
  • 5' Untranslated Regions
  • Autoantigens
  • Cross-Linking Reagents
  • Recombinant Fusion Proteins
  • Ribonucleoproteins
  • SS-B antigen
  • Transcription Factors