Inhibits the activity of interleukin-1 by binding to receptor IL1R1 and preventing its association with the coreceptor IL1RAP for signaling. Has no interleukin-1 like activity. Binds functional interleukin-1 receptor IL1R1 with greater affinity than decoy receptor IL1R2; however, the physiological relevance of the latter association is unsure. The intracellular form of IL1RN is predominantly expressed in epithelial cells. 4 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Secreted; Vesicle; Secreted, signal peptide; Cytokine
Molecular Function: cytokine activity; interleukin-1 receptor antagonist activity; interleukin-1 receptor binding; interleukin-1 Type I receptor antagonist activity; interleukin-1 Type II receptor antagonist activity; interleukin-1, Type I receptor binding; interleukin-1, Type II receptor binding; protein binding
Biological Process: acute-phase response; immune response; insulin secretion; lipid metabolic process; negative regulation of cytokine and chemokine mediated signaling pathway; negative regulation of heterotypic cell-cell adhesion; response to glucocorticoid stimulus
LTP: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.