Molecular Dissection of Human Interleukin-31-mediated Signal Transduction through Site-directed Mutagenesis |
| |
Authors: | Sabine Le Saux Fran?ois Rousseau Fabien Barbier Elisa Ravon Linda Grimaud Yannic Danger Josy Froger Sylvie Chevalier Hugues Gascan |
| |
Institution: | From the Unité Mixte INSERM 564, Bâtiment Monteclair, 4 rue Larrey, 49933 Angers Cedex 09, France |
| |
Abstract: | Interleukin (IL)-31 is a recently described cytokine, preferentially produced by T helper 2 lymphocytes and associated with skin diseases, such as atopic dermatitis. IL-31 is a member of the four α-helix bundle cytokine family and is related to the IL-6 subgroup. Its heterodimeric membrane receptor is composed of the gp130-like receptor (GPL) subunit associated to the oncostatin M receptor subunit. We identified critical amino acids implicated in the ligand receptor interaction by computational analysis combined with site-directed mutagenesis. Six IL-31 residues selected for their putative involvement in cytokine receptor contact sites were alanine-substituted, and the corresponding proteins were expressed in mammalian and bacterial systems. Biochemical, membrane binding, cell signaling, and cell proliferation analyses showed that mutation E44A, E106A, or H110A abolished IL-31 binding to GPL and the subsequent signaling events. A second ligand receptor-binding site involved Lys134, with alanine substitution leading to a protein that still binds GPL, but is unable to recruit the second receptor subunit and the subsequent signaling pathways. The results indicate that IL-31 recognizes its receptor complex through two different binding sites, and we propose a three-dimensional model for IL-31. |
| |
Keywords: | Cytokines/Interleukins Protein/Conformation Protein/Protein-Protein Interactions Protein/Structure Receptors/Cytokine Interleukin-31 |
|
|