Interleukin-1 receptor family (IPR015621)

Short name: IL-1_rcpt_fam

Overlapping homologous superfamilies


Family relationships


Interleukin-1 alpha and interleukin-1 beta (IL-1 alpha and IL-1 beta) 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. Both IL-1 receptors appear to be well conserved in evolution, and map to the same chromosomal location [PMID: 1833184]. The receptors can both bind all three forms of IL-1 (IL-1 alpha, IL-1 beta and interleukin-1 receptor antagonist, IL-1RA).

The crystal structure of the soluble extracellular part of type-I IL1R complexed with IL1RA has been determined [PMID: 9062194]. The receptor structure is characterised by three Ig-like domains, of which domains 1 and 2 are tightly linked, while domain 3 is completely separate and connected by a flexible linker.

This entry represents the interleukin-1 receptor family, which includes among others: interleukin-1 receptor type 1 (IL1R1), interleukin-1 receptor type 2 (IL1R2), interleukin-1 receptor accessory protein (IL1RAP), interleukin-18 receptor 1 and interleukin-18 receptor accessory protein.

Contributing signatures

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