CDB15:0000881 IL1B — IL1R1
Experimentally validated in Human, Mouse; Orthology-inferred in Human, Rat, Frog, Zebrafish, Chicken, Macaque, Pig, Dog, Cow, Chimp, Horse, Marmoset, Sheep, Mouse
Title
Journal:; Year Published:
Abstract
Crystal structure of the type-I interleukin-1 receptor complexed with interleukin-1beta.
Nature, 1997; PubMed, Homo sapiens IL1B — Homo sapiens IL1R1
ABSTRACT: Interleukin-1 (IL-1) is an important mediator of inflammatory disease. The IL-1 family currently consists of two agonists, IL-1alpha and IL-1beta, and one antagonist, IL-1ra. Each of these molecules binds to the type I IL-1 receptor (IL1R). The binding of IL-1alpha or IL-1beta to IL1R is an early step in IL-1 signal transduction and blocking this interaction may therefore be a useful target for the development of new drugs. Here we report the three-dimensional structure of IL-1beta bound to the extracellular domain of IL1R (s-IL1R) at 2.5 A resolution. IL-1beta binds to s-IL1R with a 1:1 stoichiometry. The crystal structure shows that s-IL1R consists of three immunoglobulin-like domains which wrap around IL-1beta in a manner distinct from the structures of previously described cytokine-receptor complexes. The two receptor-binding regions on IL-1beta identified by site-directed mutagenesis both contact the receptor: one binds to the first two domains of the receptor, while the other binds exclusively to the third domain.
IL-1 receptor accessory protein is an essential component of the IL-1 receptor.
Journal of immunology, 1998; PubMed, Mus Musculus Il1b — Mus Musculus Il1r1
ABSTRACT: The recently described IL-1R accessory protein (IL-1R AcP) interacts with IL-1beta and the IL-1 type-IR (IL-1RI), but an essential requirement for IL-1R AcP in IL-1 signaling in vitro has not been established and its role in vivo has not been examined. In this study, IL-1R AcP-deficient mice and fibroblasts were produced and characterized. All IL-1 agonists bound to IL-1R AcP-deficient cells through the type I IL-1R, but failed to activate gene expression through either the nuclear factor-kappaB or AP-1-dependent signaling pathways. Absence of IL-1R AcP differentially affected the affinity for IL-1 ligands. IL-1R AcP-deficient fibroblasts bound murine IL-1alpha and human IL-1R antagonist protein (IL-1Ra) with only moderately reduced affinity when compared with wild-type cells, whereas murine IL-1beta affinity was reduced by 70-fold. IL-1 also failed to produce a biologic response in vivo in IL-1R AcP-deficient mice. These data demonstrate that a type I IL-1R/IL-1R AcP complex is required for signaling by all IL-1 agonists and for high affinity binding by IL-1beta. Finally, IL-1R AcP is an essential signal transducing component of the functional IL-1R and should represent a novel target for blocking IL-1 function in human disease.