Influence of the hepatitis C virus 3′-untranslated region on IRES-dependent and cap-dependent translation initiation

Translation of hepatitis C virus (HCV) genomic RNA is directed by an internal ribosome entry site (IRES) in the 5′-untranslated region (5′-UTR), and the HCV 3′-UTR enhances IRES activity. Since the HCV 3′-UTR has a unique structure among 3′-UTRs, we checked possible communication between the 5′- and the 3′-UTR of HCV during translation using chimeric reporter RNAs. We show that translation directed by the HCV IRES and by the HCV-like IRES of porcine teschovirus (PTV) which belongs to a quite distinct family of viruses (picornaviruses) or by the EMCV IRES is also enhanced by the HCV 3′-UTR or by a poly(A)-tail in different cell types.