The hepatitis C virus internal ribosome-entry site: a new target for antiviral research

J Gallego1, G Varani

  • 1MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, U.K. jgs@mrc-lmb.cam.ac.uk

Insights

Hepatitis C virus (HCV) replication relies on a unique internal ribosome-entry site (IRES) mechanism. Understanding HCV IRES structure and function could lead to new antiviral therapies for this global health concern.

Area of Science:

  • Virology
  • Molecular Biology
  • Drug Discovery

Background:

  • Hepatitis C virus (HCV) is a major global cause of liver disease and mortality.
  • Current treatments for HCV infection are limited, necessitating novel therapeutic strategies.
  • HCV replication depends on an atypical translation-initiation mechanism.

Purpose of the Study:

  • To review the structure and mechanism of HCV internal ribosome-entry site (IRES) mediated translation initiation.
  • To explore the potential of the HCV IRES as a target for developing new antiviral drugs.

Main Methods:

  • Review of existing scientific literature on HCV IRES structure and function.
  • Analysis of the molecular interactions involved in cap-independent translation initiation.
  • Evaluation of the HCV IRES as a potential antiviral target.

Main Results:

  • The HCV IRES facilitates cap-independent initiation of viral protein synthesis.
  • Specific recognition of the IRES by the small ribosomal subunit and eukaryotic initiation factor 3 is crucial.
  • The unique mechanism presents a potential vulnerability for therapeutic intervention.

Conclusions:

  • The HCV IRES is a critical component of viral replication.
  • Targeting the HCV IRES offers a promising avenue for novel antiviral drug development.
  • Further research into IRES structure and function may yield effective HCV treatments.

Related Concept Videos

Hepatitis01:25

Hepatitis

Hepatitis is an inflammatory condition of the liver most commonly caused by hepatotropic viruses (A–E), though non-infectious causes such as alcohol and drugs also exist.Hepatitis AHepatitis A virus (HAV) is a non-enveloped RNA virus of the Picornaviridae family. It is primarily transmitted via the fecal-oral route, typically through ingestion of contaminated food or water. After ingestion, HAV enters the bloodstream through the oropharynx or intestinal epithelium and reaches the liver. The...
Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
Inhibitors Of Virion Release01:25

Inhibitors Of Virion Release

Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated...
Antiviral Nucleoside Inhibitors01:22

Antiviral Nucleoside Inhibitors

Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),...
Viral Hepatitis I: Introduction01:28

Viral Hepatitis I: Introduction

Viral hepatitis is an inflammatory condition of the liver caused by infection with hepatotropic viruses, most commonly hepatitis A, B, C, D, and E. Despite variations in structure and transmission, all viruses mentioned infect hepatocytes and provoke immune responses that can hinder liver function. Additionally, some non-hepatotropic viruses can also lead to hepatic inflammation.Hepatitis A VirusHepatitis A virus (HAV) is transmitted through the fecal–oral route, typically by ingestion of food...
Inhibitors of Virion Maturation and Assembly01:19

Inhibitors of Virion Maturation and Assembly

As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...