Recombinant baculovirus-expressed NS3 proteinase of hepatitis C virus shows activity in cell-based and in vitro assays.
Recombinant baculoviruses have been constructed which express the hepatitis C virus (HCV) NS3 proteinase and its substrates in insect cells. The expressed proteinase has been shown to carry out trans-cleavage at the NS3/4A, NS4A/4B, NS4B/5A and NS5A/5B junctions in a cell-based assay. When assayed in a cell-free system using in vitro translated substrates, the proteinase could perform trans-processing of the NS4A/4B and NS5A/5B junctions, but only when coexpressed with NS4A, either as an NS3-4A precursor or by co-infection of cells with NS3- and NS4A-expressing recombinant baculoviruses. Possible reasons for the absolute requirement of the NS3 proteinase for NS4A in vitro are discussed.
Overton
H
H
Department of Molecular Virology, Roche Products Ltd, Welwyn Garden City, UK.
McMillan
D
D
Gillespie
F
F
Mills
J
J
D000818:Animals; D002460:Cell Line; D002474:Cell-Free System; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics; D016174:Hepacivirus / Q000201:enzymology*; D017924:Nucleopolyhedroviruses / Q000235:genetics*; D011498:Protein Precursors / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012697:Serine Endopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018411:Spodoptera; D017361:Viral Nonstructural Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D011498:Protein Precursors; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases