title: A hot spot on interferon α/β receptor subunit 1 (IFNAR1) underpins its interaction with interferon-β and dictates signaling.
abstract: The interaction of IFN-β with its receptor IFNAR1 (interferon α/β receptor subunit 1) is vital for host-protective anti-viral and anti-proliferative responses, but signaling via this interaction can be detrimental if dysregulated. Whereas it is established that IFNAR1 is an essential component of the IFNAR signaling complex, the key residues underpinning the IFN-β-IFNAR1 interaction are unknown. Guided by the crystal structure of the IFN-β-IFNAR1 complex, we used truncation variants and site-directed mutagenesis to investigate domains and residues enabling complexation of IFN-β to IFNAR1. We have identified an interface on IFNAR1-subdomain-3 that is differentially utilized by IFN-β and IFN-α for signal transduction. We used surface plasmon resonance and cell-based assays to investigate this important IFN-β binding interface that is centered on IFNAR1 residues Tyr240and Tyr274binding the C and N termini of the B and C helices of IFN-β, respectively. Using IFNAR1 and IFN-β variants, we show that this interface contributes significantly to the affinity of IFN-β for IFNAR1, its ability to activate STAT1, the expression of interferon stimulated genes, and ultimately to the anti-viral and anti-proliferative properties of IFN-β. These results identify a key interface created by IFNAR1 residues Tyr240and Tyr274interacting with IFN-β residues Phe63, Leu64, Glu77, Thr78, Val81, and Arg82that underlie IFN-β-IFNAR1-mediated signaling and biological processes.
authors.affiliation: From the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia, nicole.deweerd@hudson.org.au.|Department of Molecular and Translational Sciences, School of Clinical Sciences at Monash Health, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: de Weerd
authors.affiliation: From the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia.|Department of Molecular and Translational Sciences, School of Clinical Sciences at Monash Health, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: Antony Y
authors.initials: AY
authors.lastname: Matthews
authors.affiliation: From the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: Phillip R
authors.initials: PR
authors.lastname: Pattie
authors.affiliation: From the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia.|Department of Molecular and Translational Sciences, School of Clinical Sciences at Monash Health, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: Nollaig M
authors.initials: NM
authors.lastname: Bourke
authors.affiliation: From the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia.|Department of Molecular and Translational Sciences, School of Clinical Sciences at Monash Health, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: San S
authors.initials: SS
authors.lastname: Lim
authors.affiliation: Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia.|Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia, and.
authors.forename: Julian P
authors.initials: JP
authors.lastname: Vivian
authors.affiliation: Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia.|Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia, and.|Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, United Kingdom.
authors.forename: Jamie
authors.initials: J
authors.lastname: Rossjohn
authors.affiliation: From the Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Victoria 3168, Australia, paul.hertzog@hudson.org.au.|Department of Molecular and Translational Sciences, School of Clinical Sciences at Monash Health, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Hertzog
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D020125:Mutation, Missense; D000072417:Protein Domains; D053633:Receptor, Interferon alpha-beta / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: C508032:Ifnar1 protein, mouse; D053633:Receptor, Interferon alpha-beta; D016899:Interferon-beta
keywords: interferon; mutagenesis; receptor; signal transduction; structure-function