title: Evidence for ligand-independent multimerization of the IL-17 receptor.
abstract: IL-17 and its receptor are founding members of a novel inflammatory cytokine family. To date, only one IL-17 receptor subunit has been identified, termed IL-17RA. All known cytokine receptors consist of a complex of multiple subunits. Although IL-17-family cytokines exist as homodimers, the configuration and stoichiometry of the IL-17R complex remain unknown. We used fluorescence resonance energy transfer (FRET) to determine whether IL-17RA subunits multimerize, and, if so, whether they are preassembled in the plasma membrane. HEK293 cells coexpressing IL-17RA fused to cyan or yellow fluorescent proteins (CFP or YFP) were used to evaluate FRET before and after IL-17A or IL-17F treatment. In the absence of ligand, IL-17RA molecules exhibited significant specific FRET efficiency, demonstrating that they exist in a multimeric, preformed receptor complex. Strikingly, treatment with IL-17A or IL-17F markedly reduced FRET efficiency, suggesting that IL-17RA subunits within the IL-17R complex undergo a conformational change upon ligand binding.
authors.affiliation: Department of Oral Biology, School of Dental Medicine, University at Buffalo, State University of New York, Buffalo, NY 14214, USA.
authors.forename: Jill M
authors.initials: JM
authors.lastname: Kramer
authors.forename: Ling
authors.initials: L
authors.lastname: Yi
authors.forename: Fang
authors.initials: F
authors.lastname: Shen
authors.forename: Amarnath
authors.initials: A
authors.lastname: Maitra
authors.forename: Xuanmao
authors.initials: X
authors.lastname: Jiao
authors.forename: Tian
authors.initials: T
authors.lastname: Jin
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Gaffen
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D031541:Fluorescence Resonance Energy Transfer; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D020381:Interleukin-17 / Q000378:metabolism*; D008024:Ligands; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D046912:Multiprotein Complexes; D020836:Protein Structure, Quaternary; D021122:Protein Subunits; D018123:Receptors, Interleukin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D001426:Bacterial Proteins; C485182:Cyan Fluorescent Protein; D020381:Interleukin-17; D008024:Ligands; D008164:Luminescent Proteins; D046912:Multiprotein Complexes; D021122:Protein Subunits; D018123:Receptors, Interleukin; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins