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

Hepatitis C virus non-structural protein 4B (NS4B) is a 27-kDa hydrophobic integral membrane protein essential for the viral life cycle (UniProt P26664). Its primary function is to induce the formation of the "membranous web," a specialized cytoplasmic structure derived from the endoplasmic reticulum that serves as a scaffold for the viral replication complex (Egger et al., 2002, J. Virol.). NS4B also exhibits NTPase activity and RNA-binding capabilities, which are critical for the assembly and function of the replication machinery (Einav et al., 2004, J. Virol.). In the context of disease, NS4B is indispensable for the replication of the Hepatitis C virus, which causes chronic liver inflammation, cirrhosis, and hepatocellular carcinoma (Gouttenoire et al., 2010, J. Gen. Virol.). While most current direct-acting antivirals target NS3/4A, NS5A, or NS5B, NS4B remains a significant target for drug development due to its unique role in organelle remodeling. Experimental inhibitors like clemizole and ACH-806 have demonstrated the potential to disrupt viral replication by targeting NS4B, although challenges such as drug resistance and toxicity have hindered clinical progression (Einav et al., 2008, Nature Medicine; Hafenrichter et al., 2014).

Other names

NS4Bp27HCV NS4BNon-structural protein 4B

Inhibition of the formation of the membranous web and disruption of the viral RNA replication complex by interfering with NS4B-RNA binding or its NTPase activity (Einav et al., 2008, Nature Medicine; Paul et al., 2011, J. Virol.).