Poly(C)-binding protein interacts with the hepatitis C virus 5 ' untranslated region

We have investigated whether poly(C)-binding protein (PCBP)-1 and PCBP-2 in teract with the hepatitis C virus (HCV) 5 untranslated region. Our results demonstrate that glutathione S-transferase (GST)-PCBP-1 and GST-PCBP-2 fusi on proteins bind specifically to the HCV 5' untranslated region. An antiser um raised against PCBP-2 induced a supershift after incubation with RNA-pro tein complexes formed between proteins in a HeLa cell cytoplasmic extract a nd the HCV 5' untranslated region, indicating that this interaction occurs intracellularly. The complete internal ribosome entry site was necessary fo r efficient binding, suggesting that maintenance of the secondary structure was necessary for recognition of the binding site by the PCBPs.