Hepatitis C virus 5' untranslated region (HCV 5'UTR) (HCV 5'UTR)

The Hepatitis C virus 5' untranslated region (HCV 5'UTR) is a highly conserved, non-coding segment of the HCV RNA genome approximately 341 nucleotides long (Lukavsky, 2009). It plays a critical role in the viral life cycle by harboring the Internal Ribosome Entry Site (IRES), which facilitates cap-independent translation of the viral polyprotein by directly recruiting the host's 40S ribosomal subunit (Niepmann, 2013). Additionally, the 5'UTR contains specific binding sites for the liver-specific microRNA-122 (miR-122), which is essential for protecting the viral RNA from degradation and promoting its replication (Jopling et al., 2005). Because of its high conservation across genotypes and its essentiality for viral protein synthesis and stability, the 5'UTR is a prime therapeutic target. Pharmacological strategies include antisense oligonucleotides like Miravirsen that sequester miR-122, effectively starving the virus of a necessary host factor (Janssen et al., 2013). Other approaches involve ribozymes or small molecules designed to disrupt the complex secondary and tertiary structures of the IRES to halt viral protein production.

Other names

HCV 5' non-coding regionHCV 5' NCRHepatitis C virus internal ribosome entry siteHCV IRES

Inhibition of IRES-mediated translation initiation; Sequestration of host microRNA-122 to prevent viral RNA stabilization and replication; Cleavage of viral RNA via ribozymes or RNase H-mediated antisense activity.