Hepatitis C virus non-structural protein 4B-RNA complex (HCV NS4B-RNA complex) (HCV NS4B-RNA complex)

The Hepatitis C virus (HCV) non-structural protein 4B (NS4B) is a 27-kDa hydrophobic integral membrane protein that plays a central role in the viral life cycle by inducing the formation of the membranous web, which serves as the scaffold for viral RNA replication (UniProt P26664). A critical biochemical function of NS4B is its specific binding to the 3' terminus of the HCV negative-strand RNA, an interaction that is essential for the assembly and activity of the viral replication complex (PubMed: 18677322). This NS4B-RNA complex is considered a viable therapeutic target because disrupting this interaction effectively halts the production of new viral genomes. The drug clemizole, originally an antihistamine, was identified as a potent inhibitor of this specific protein-RNA interaction, leading to a decrease in HCV replication in cell culture models (Nature Medicine, 2008). While most current direct-acting antivirals (DAAs) target the NS3 protease or NS5B polymerase, inhibitors of the NS4B-RNA complex offer a complementary mechanism of action that could help overcome resistance to existing therapies. However, the high genetic variability of HCV remains a significant challenge, as mutations in the NS4B gene can lead to drug resistance and reduced binding affinity for inhibitors (PubMed: 21165465).

Other names

HCV NS4B-RNA interactionNS4B-RNA binding complexHepatitis C virus NS4B-RNA complex

Inhibition of the binding between the HCV NS4B protein and the 3' terminus of the viral negative-strand RNA, thereby disrupting the formation of the viral replication complex (PubMed: 18677322).