IL1RL1

Interleukin 1 receptor-like 1, also known as IL1RL1 and ST2, is a is_associated_with::protein that in humans is encoded by the IL1RL1 is_associated_with::gene.

Function
IL1RL1 is a member of the is_associated_with::Toll-like receptor superfamily. However unlike other members of the family IL1RL1 does not induce an inflammatory response through activation of is_associated_with::NF-κB, although it does activate is_associated_with::MAP kinases.

ST2 is a member of the interleukin 1 receptor family. The ST2 protein has two isoforms and is directly implicated in the progression of cardiac disease: a soluble form (referred to as soluble ST2 or sST2) and a membrane-bound receptor form (referred to as the ST2 receptor or ST2L). The ligand for ST2 is the cytokine Interleukin-33(IL-33). Binding of IL-33 to the ST2 receptor, in response to cardiac disease or injury, such as an ischemic event, elicits a cardioprotective effect resulting in preserved cardiac function. This cardioprotective IL-33 signal is counterbalanced by the level of soluble ST2, which binds IL-33 and makes it unavailable to the ST2 receptor for cardioprotective signaling. As a result, the heart is subjected to greater stress in the presence of high levels of soluble ST2.

Molecular biology
The gene is found on the long arm of Chromosome 2 (2q12). It is 40,536 bases long and is located on the Watson (plus) strand. It encodes a protein of 556 amino acids (molecular weight 63,358 Da). Both membrane bound and soluble forms are known. The protein is known to interact with is_associated_with::MyD88, is_associated_with::IRAK1, is_associated_with::IRAK4 and is_associated_with::TRAF6. It appears to be essential for the normal function of T helper cells type 2 (Th2 cells).

Clinical significance
Mutations in this gene have been linked to is_associated_with::atopic dermatitis and is_associated_with::asthma.

The protein encoded by this gene serves as a cardiac biomarker.