• Open Access

In silico directed mutagenesis identifies the CD81/claudin-1 hepatitis C virus receptor interface

Authors

  • Christopher Davis,

    1. School of Immunity and Infection, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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  • Helen J. Harris,

    1. School of Immunity and Infection, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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  • Ke Hu,

    1. School of Immunity and Infection, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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  • Heidi E. Drummer,

    1. Viral Fusion Laboratory, Burnet Institute, Melbourne, Vic., Australia
    2. Department of Microbiology, Monash University, Clayton, Vic., Australia
    3. Department of Microbiology and Immunology, Melbourne University, Parkville, Vic., Australia
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  • Jane A. McKeating,

    1. School of Immunity and Infection, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
    2. NIHR Liver Biomedical Research Unit, University of Birmingham, Birmingham, UK
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  • Jonathan G. L. Mullins,

    1. Genome and Structural Bioinformatics, Institute of Life Science, College of Medicine, Swansea University, Swansea, Wales, UK
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    • Shared senior authorship.
  • Peter Balfe

    Corresponding author
    • School of Immunity and Infection, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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    • Shared senior authorship.

For correspondence. E-mail p.balfe@bham.ac.uk; Tel. (+44) 121 414 8174; Fax (+44) 121 414 3599.

Summary

Hepatitis C virus (HCV) entry is dependent on host cell molecules tetraspanin CD81, scavenger receptor BI and tight junction proteins claudin-1 and occludin. We previously reported a role for CD81/claudin-1 receptor complexes in HCV entry; however, the molecular mechanism(s) driving association between the receptors is unknown. We explored the molecular interface between CD81 and claudin-1 using a combination of bioinformatic sequence-based modelling, site-directed mutagenesis and Fluorescent Resonance Energy Transfer (FRET) imaging methodologies. Structural modelling predicts the first extracellular loop of claudin-1 to have a flexible beta conformation and identifies a motif between amino acids 62–66 that interacts with CD81 residues T149, E152 and T153. FRET studies confirm a role for these CD81 residues in claudin-1 association and HCV infection. Importantly, mutation of these CD81 residues has minimal impact on protein conformation or HCVglycoprotein binding, highlighting a new functional domain of CD81 that is essential for virus entry.

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