title: Host cell factor requirement for hepatitis C virus enzyme maturation.
abstract: The cellular chaperone, HSP90, is identified here as an essential factor for the activity of NS2/3 protease of hepatitis C virus. The cleavage activity of NS2/3 protease synthesized in reticulocyte lysate is ATP-dependent, as evidenced by ATP depletion experiments and inhibition with nonhydrolyzable ATP analogs. Geldanamycin and radicicol, ATP-competitive inhibitors of the chaperone HSP90, also inhibit the cleavage of in vitro-synthesized NS2/3. Furthermore, these HSP90 inhibitors prevent NS2/3 cleavage when the protease is expressed in mammalian cells. The physical association of NS2/3 with HSP90 is demonstrated by immunoprecipitation. Thus, by way of a chaperone/folding activity, an HSP90-containing complex is required for maturation of the polyprotein that encodes the enzymes essential for hepatitis C virus replication.
authors.affiliation: Department of Structural Biology, Merck Research Laboratories, West Point, PA 19486, USA.
authors.forename: L
authors.initials: L
authors.lastname: Waxman
authors.forename: M
authors.initials: M
authors.lastname: Whitney
authors.forename: B A
authors.initials: BA
authors.lastname: Pollok
authors.forename: L C
authors.initials: LC
authors.lastname: Kuo
authors.forename: P L
authors.initials: PL
authors.lastname: Darke
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D016227:Benzoquinones; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016174:Hepacivirus / Q000201:enzymology*; D006801:Humans; D019169:Jurkat Cells; D047029:Lactams, Macrocyclic; D007783:Lactones / Q000494:pharmacology; D018942:Macrolides; D011499:Protein Processing, Post-Translational; D011809:Quinones / Q000378:metabolism / Q000494:pharmacology
chemical_list: D016227:Benzoquinones; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D007783:Lactones; D018942:Macrolides; D011809:Quinones; D000255:Adenosine Triphosphate; D003546:Cysteine Endopeptidases; C107824:NS2-3 protease; C035359:monorden; C001277:geldanamycin