Suppression of hepatitis C virus replication by protein kinase C-related kinase 2 inhibitors that block phosphorylation of viral RNA polymerase.
Hepatitis C virus (HCV) infection is a serious threat to human health worldwide. In spite of the continued search for specific and effective anti-HCV therapies, the rapid emergence of drug-resistance variants has been hampering the development of anti-HCV drugs designed to target viral enzymes. Targeting host factors has therefore emerged as an alternative strategy offering the potential to circumvent the ever-present complication of drug resistance. We previously identified protein kinase C-related kinase 2 (PRK2) as a cellular kinase that phosphorylates the HCV RNA-dependent RNA polymerase (RdRp). Here, we report the anti-HCV activity of HA1077, also known as fasudil, and Y27632, which blocks HCV RdRp phosphorylation by suppressing PRK2 activation. Treatment of a Huh7 cell line, stably expressing a genotype 1b HCV subgenomic replicon RNA, with 20 microm each of HA1077 and Y27632 reduced the HCV RNA level by 55% and 30%, respectively. A combination of the inhibitors with 100 IU/mL interferon alpha (IFN-alpha) significantly potentiated the anti-HCV drug activities resulting in approximately a 2-log(10) viral RNA reduction. We also found that IFN-alpha does not activate PRK2 as well as its upstream kinase PDK1 in HCV-replicating cells. Furthermore, treatment of HCV-infected cells with 20 microm each of HA1077 and Y27632 reduced the levels of intracellular viral RNA by 70% and 92%, respectively. Taken together, the results identify PRK2 inhibitors as potential antiviral drugs that act by suppressing HCV replication via inhibition of viral RNA polymerase phosphorylation.
Kim
S-J
SJ
Department of Biotechnology, Yonsei University, Seoul, Korea.
Kim
J-H
JH
Sun
J-M
JM
Kim
M-G
MG
Oh
J-W
JW
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000577:Amides / Q000494:pharmacology*; D002460:Cell Line; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D016174:Hepacivirus / Q000187:drug effects*; D022781:Hepatocytes / Q000821:virology; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D014764:Viral Proteins / Q000378:metabolism*; D014779:Virus Replication / Q000187:drug effects*
D000577:Amides; D016898:Interferon-alpha; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D014764:Viral Proteins; C108830:Y 27632; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C061570:protein kinase N; D011493:Protein Kinase C; D012321:DNA-Directed RNA Polymerases; C049347:fasudil