The molecular studies of HCV RNA replication and translation

Restricted until 12 May. 2010.Hepatitis C virus RNA replication requires not only the viral replicase but also the host cytoskeletons, membrane structures, and cellular factors. Several hnRNPs, such as polypyrimidin-tract-binding protein (PTB) and La autoantigen were found to regulate both HCV RNA replication and translation. Another hnRNP, SYNCRIP (synaptotamin-Binding, Cytoplasmic RNA-Interacting Protein, or NSAP-1), was found to regulate HCV-IRES dependent translation. In my first part of dissertation, we identified SYNCRIP as a positive regulator of HCV RNA replication.; With a growing number of "dual-function" proteins which are able to regulate HCV RNA translation and replication, it is interesting to investigate how the two important steps in HCV life cycle are temporally and spatially regulated. Therefore, we initiated a series of experiments to examine if HCV RNA translation is dependent on its replication. The colocalization of newly-synthesized viral RNA and peptide were detected in live cell and under electronmicroscopy. It is also found that the replication-deficient replicon or full-length HCV RNA has deficiency in translation as well. Our findings together suggest that the replication and translation of HCV RNA are coupled and occur in the same cellular compartments termed "replicasome"