title: Role of La autoantigen and polypyrimidine tract-binding protein in HCV replication.
abstract: To determine if the cellular factors La autoantigen (La) and polypyrimidine tract-binding protein (PTB) are required for hepatitis C virus (HCV) replication, we used siRNAs to silence these factors and then monitored their effect on HCV replication using quantitative RT-PCR. In addition, we determined the influence of PTB on the activity of the 3' noncoding region (NCR) of HCV and investigated its interaction with the components of the HCV replicase complex. We found that La is essential for efficient HCV replication while PTB appears to partially repress replication. PTB does, however, block the binding of HCV RNA-dependent RNA polymerase (RdRp, NS5B) to the 3'NCR. Indirect immunofluorescence microscopy showed co-localization of cytoplasmic PTB with the HCV RdRp in hepatoma cells (Huh-7) expressing HCV proteins, while in vitro translation of viral proteins from the HCV replicon revealed the interaction of PTB isoforms with NS5B polymerase and NS3.
authors.affiliation: Program in Molecular Biology, Department of Microbiology, B172, University of Colorado Health Sciences Center, 4200 E. 9th Avenue, Denver, CO 80262, USA.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Domitrovich
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Diebel
authors.forename: Naushad
authors.initials: N
authors.lastname: Ali
authors.forename: Shameema
authors.initials: S
authors.lastname: Sarker
authors.forename: Aleem
authors.initials: A
authors.lastname: Siddiqui
mesh_terms: D020413:3' Untranslated Regions / Q000378:metabolism; D001324:Autoantigens; D001483:Base Sequence; D045744:Cell Line, Tumor; D016174:Hepacivirus / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D038941:Polypyrimidine Tract-Binding Protein / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D034741:RNA, Small Interfering / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D017361:Viral Nonstructural Proteins / Q000378:metabolism; D014779:Virus Replication; D000097585:SS-B Antigen; D012324:RNA-Dependent RNA Polymerase
chemical_list: D020413:3' Untranslated Regions; D001324:Autoantigens; D038941:Polypyrimidine Tract-Binding Protein; D034741:RNA, Small Interfering; D012261:Ribonucleoproteins; D017361:Viral Nonstructural Proteins; D000097585:SS-B Antigen; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase