In silico directed mutagenesis identifies the CD81/claudin-1 hepatitis C virus receptor interface.
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 HCV glycoprotein binding, highlighting a new functional domain of CD81 that is essential for virus entry.
School of Immunity and Infection, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
Christopher
C
Davis
Helen J
HJ
Harris
Ke
K
Hu
Heidi E
HE
Drummer
Jane A
JA
McKeating
Jonathan G L
JG
Mullins
Peter
P
Balfe
D000818:Animals; D002460:Cell Line; D062445:Claudin-1 / Q000235:genetics / Q000502:physiology*; D019295:Computational Biology; D003198:Computer Simulation; D031541:Fluorescence Resonance Energy Transfer; D016174:Hepacivirus / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011991:Receptors, Virus / Q000235:genetics / Q000502:physiology*; D060225:Tetraspanin 28 / Q000235:genetics / Q000502:physiology*; D053586:Virus Internalization
C554798:CD81 protein, human; D062445:Claudin-1; D011991:Receptors, Virus; D060225:Tetraspanin 28