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


CONCLUSIONS
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.
Spångberg
K
K
Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala University, Sweden.
Goobar-Larsson
L
L
Wahren-Herlenius
M
M
Schwartz
S
S
D020413:3' Untranslated Regions / Q000378:metabolism*; D020121:5' Untranslated Regions / Q000378:metabolism*; D001324:Autoantigens / Q000235:genetics / Q000378:metabolism*; D001667:Binding, Competitive; D015153:Blotting, Western; D002478:Cells, Cultured; D003432:Cross-Linking Reagents; D016174:Hepacivirus / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014466:Ultraviolet Rays; D000097585:SS-B Antigen
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D001324:Autoantigens; D003432:Cross-Linking Reagents; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; D000097585:SS-B Antigen