The Hepatitis C Virus E2p7 localization and topology in a recombinant system

The Hepatitis C virus (HCV) genome encodes a polyprotein that is processed co- and posttranslationally. Incomplete processing at the E2/p7 junction generates the E2p7 product. Using a recombinant system, we analysed the processing, localization and topology of E2p7. By immunoprecipitation of proteins expressed by metabolically labelled cells, we confirm that E2p7 is a precursor of E2. E2p7 forms a native-like heterodimer with E1, and it is localized entirely to the endoplasmic reticulum, in contrast to fully processed E2 and p7 that leak to the plasma membrane. No change in the topology of p7 was observed upon processing of E2p7, indicating that incomplete cleavage at the E2/p7 site is not regulated by changes in p7 membrane topology