It is a group of structurally homologous proteins, conserved throughout the species as it was identified from plants to mammals.
Proteins of this family play important role in host defence, injury and stress.
There are minimal homologies in amino acid sequences of Ig-like domains between proteins of IL-1R family but they all show characteristic Ig-fold and two β-sheets joined together by disulfide bonds which form between cysteine residues.
[2] After ligand binding, the first step of IL-1R family signalling is oligomerization of TIR domains present on receptors (IL-1R, TLR), coreceptors (IL-1R accessory protein, CD14) and adaptor molecules (MyD88).
The signal is transduced by cytoplasmatic kinases (such as IRAKs) and by other adaptors, such as tumor necrosis factor 6 (TRAF6).
NF-κB is translocated into nucleus and by binding DNA intermediates inflammatory, alergic and non-alergic immune response.
[10] It can be also regulated on the level of downstream signalling molecules by inhibiting recruitment of IRAKs, or by suppression of MyD88 secretion.
By forming a receptor heterodimer with IL-1RI facilitates signalization due to oligomerization of TIR domains of these proteins.
In response to stress or acute phase induction, a soluble form of this protein is produced by alternative splicing.