Recombinant Human IL-1 RAcP/IL-1R3 ST2/IL-33R Fc Protein, CF

Recombinant Human IL-1 RAcP/IL-1R3 ST2/IL-33R Fc Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background:

Serum stimulation-2 (ST2), also known as IL-1RL1, heterodimerizes with IL1-R3, also referred to as IL-1RAP, IL-1R3, or C3orf13, after binding IL-33 (1). The 556 aa human ST2 contains an 18 aa signal peptide sequence, 310 amino acid (aa) extracellular domain, 21 aa transmembrane region, and 207 cytoplasmic domain. ST2 contains three extracellular IgG domains and an intracellular TIR domain. The 570 aa human 1L-1R3 contains a 20 aa signal peptide sequence, 347 aa extracellular domain, 21 aa transmembrane region, and 182 cytoplasmic domain. Differential promoter binding of ST2 generates two main splice variants, a membrane-bound receptor (ST2) expressed on cardiomyocytes and a variety of immune cells that promotes NF-kappa B signaling and a soluble form (sST2) that prevents its signaling, which can be produced spontaneously by lung, kidney, heart, and small intestine cells or by activated mast cells and TH2 cells (2). Two less well understood ST2 splice variants include ST2V, expressed highly in gastrointestinal organs (3), and ST2LV, secreted by eye, heart, lung, and liver tissues (4). Within the ECD, human ST2 shares 68% and 64% aa sequence identity with mouse and rat ST2, and human 1L-1R3 has 86% and 94% aa sequence identity with mouse and rat IL-1R3. After ST2 binds to IL-33 and heterodimerization with IL-1R3, the TIR domain can be activated by MyD88 and IL-1R-associated kinase activation to activate MAPK or NF-kappa B pathways (1). While the mechanisms/signals are unclear, TRAF6 is required for NF-kappa B but not for MAPK activation (5). ST2 participates in a variety of disease implications, especially with its association with immune cells. For example, IL-33 signaling through ST2 is involved with lung diseases in allergic asthma (6), both participating in inflammation but also in its maintenance (7). With skin diseases, upregulation of ST2 and IL-33 has been observed with atopic dermatitis (8), psoriasis (9), and vitiligo (10).