Interleukin-1 receptor antagonist protein (IPR027166)

Short name: IL-1RA

Family relationships


Interleukin-1 alpha and interleukin-1 beta (IL-1A and IL-1B) are cytokines that participate in the regulation of immune responses, inflammatory reactions, and hematopoiesis [PMID: 2969618].

Two types of IL-1 receptor, each with three extracellular immunoglobulin (Ig)-like domains, limited sequence similarity (28%) and different pharmacological characteristics have been cloned from mouse and human cell lines: these have been termed type I and type II receptors [PMID: 8702856]. The receptors both exist in transmembrane (TM) and soluble forms: the soluble IL-1 receptor is thought to be post-translationally derived from cleavage of the extracellular portion of the membrane receptors.

Interleukin-1 receptor antagonist (IL-1RA) binds to the IL-1 receptor, blocking the effects of IL-1A and IL-1B, whilst eliciting no response of its own. From sequence comparisons, it seems to have arisen by gene duplication before IL-1 diverged into IL-1A and IL-1B, as it has features of both [PMID: 1828896]. It seems likely to have the same fold as IL-1A and IL-1B.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005152 interleukin-1 receptor antagonist activity
GO:0005149 interleukin-1 receptor binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.