IL-33 Mouse Active Protein

Function: Cytokine that binds to and signals through IL1RL1/ST2 and its stimulation recruits MYD88, IRAK1, IRAK4, and TRAF6, followed by phosphorylation of MAPK3/ERK1 and/or MAPK1/ERK2, MAPK14, and MAPK8

By similarity. Induces T-helper type 2-associated cytokines. Acts as a chemoattractant tor Th2 cells, and may function as an "alarmin", that amplifies immune responses during tissue injury. Ref.1 Ref.4In quiescent endothelia the uncleaved form is constitutively and abundantly expressed, and acts as a chromatin-associated nuclear factor with transcriptional repressor properties, it may sequester nuclear NF-kappaB/RELA, lowering expression of its targets. This form is rapidely lost upon angiogenic or proinflammatory activation. Ref.1 Ref.4

Subunit structure: Forms a 1:1:1 heterotrimeric complex with its primary high-affinity receptor IL1RL1 and the coreceptor IL1RAP

By similarity.

Subcellular location: Nucleus. Chromosome. Cytoplasmic vesicle › secretory vesicle

By similarity. Secreted. Note: Associates with heterochromatin and mitotic chromosomes. Translocation from the nucleus occurs upon biomechanical strain, depends on an intact microtubule network, and is ATP-dependent

By similarity. Ref.4

Domain: The homeodomain-like HTH domain mediates nuclear localization and heterochromatin association

By similarity.

Post-translational modification: Proteolytically converted to a mature form by CASP1 in vitro and calpains in vivo. Caspase-mediated proteolysis, once thought to activate IL33, rather acts as a switch to dampen its activity. Proteolysis is not strictly required for biological activity

By similarity.

Miscellaneous: Intraperitoneal injections of IL-33 induce the expression of IL-4, IL-5, and IL-13 and lead to severe pathological changes in mucosal organs.

Sequence similarities: Belongs to the IL-1 family. Highly divergent.