Interleukin-1 receptor antagonist/Interleukin-36 (IPR003297)

Short name: IL-1RA/IL-36

Overlapping homologous superfamilies

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.

Interleukin-36 cytokines constitute a novel cluster of cytokines with structural and functional similarities to IL-1 [PMID: 23029241]. Previously designated as interleukin-1 family members 5 - 10 (IL-1F5 to IL-1F10), they have recently been reclassified according to an updated cytokine nomenclature scheme [PMID: 20959797]. Family members include:

  • interleukin-36 alpha, beta and gamma (previously IL-1F6, IL-1F8 and IL-1F9, respectively), which are pro-inflammatory and signal through IL-1Rrp2 and IL-1RAcP [PMID: 14734551].
  • interleukin-36 receptor antagonist (previously IL-1F5), which binds IL-1Rrp2, acting as an antagonist for interleukins signalling via this route [PMID: 17908936].
  • interleukin-37 (IL-1F7), which exerts anti-inflammatory actions by suppressing production of pro-inflammatory cytokines [PMID: 20935647].
  • IL-1F10, whose function is unknown.

This entry represents IL-1RA and Interleukin-36 cytokines.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

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.