Protein kinase C recognizes the protein kinase A-binding motif of nonstructural protein 3 of hepatitis C virus.
The nonstructural protein 3 (NS3) of hepatitis C virus (HCV) inhibits the nuclear transport and the enzymatic activity of the catalytic subunit of protein kinase A. This inhibition is mediated by an arginine-rich domain localized between amino acids 1487-1500 of the HCV polyprotein. The data presented here indicate that the arginine-rich domain, when embedded in recombinant fragments of NS3, interacts with the catalytic site of protein kinase C (PKC) and inhibits the phosphorylation mediated by this enzyme in vitro and in vivo. Furthermore, a direct binding of PKC to the NS3 fragments leads to an inhibition of the free shuttling of the kinase between the cytoplasm and the particulate fraction. In contrast, a peptide corresponding to the arginine-rich domain (HCV (1487-1500)), despite also being a PKC inhibitor, did not influence the PKC shuttling process and was transported to the particulate fraction by the translocating kinase upon activation with tetradecanoylphorbol-13-acetate. Using the tetradecanoylphorbol-13-acetate -stimulated respiratory burst of NS3-introduced neutrophils as a model system, we could demonstrate that NS3 is able to block PKC-mediated functions within intact cells. Our data support the possibility that NS3 disrupts the PKC-mediated signal transduction.
Borowski
P
P
Abteilung für Virologie, Bernhard-Nocht-Institut für Tropenmedizin, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany.
Schulze zur Wiesch
J
J
Resch
K
K
Feucht
H
H
Laufs
R
R
Schmitz
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D003001:Cloning, Molecular; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation; D016174:Hepacivirus / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009504:Neutrophils / Q000201:enzymology / Q000821:virology; D010446:Peptide Fragments / Q000737:chemistry; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000378:metabolism*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D001120:Arginine; D017868:Cyclic AMP-Dependent Protein Kinases; D010446:Peptide Fragments; D011493:Protein Kinase C; D011994:Recombinant Proteins; D013755:Tetradecanoylphorbol Acetate; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases