The hepatitis C virus NS2/3 protein is a highly hydrophobic protease responsible for the cleavage of the viral polypeptide between non-structural proteins NS2 and NS3. However, many aspects of the NS2/3 protease’s role in the viral life cycle and mechanism of action remain unknown or controversial. NS2/3 has been proposed to function as either a cysteine or metalloprotease despite its lack of sequence homology to proteases of known function. In addition, although shown to be required for persistent infection in a chimpanzee, the role of NS2/3 cleavage in the viral life cycle has not yet been fully investigated due to the lack of an in vitro system in which to study all aspects of HCV replication. However, several recent studies are beginning to clarify possible roles of the cleaved NS2 protein in modulation of host cell gene expression and apoptosis.
Copyright © 2006, Horizon Bioscience.