Recombinant Rat IL-21R Fc Chimera Protein, CF

Recombinant Rat IL-21R Fc Chimera 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: IL-21R

IL-21 R (interleukin-21 receptor) is a type I transmembrane glycoprotein that belongs to the class I cytokine receptor family, type 4 subfamily (1 ‑ 5). Complex formation between IL-21 R and the common gamma chain ( gamma _c), also used for IL-2, IL-4, IL-7, IL-9, and IL-15 receptors, is required for signaling (6, 7). Rat IL-21 R cDNA encodes a 521 amino acid (aa) precursor that contains a 19 aa signal peptide, a 218 aa extracellular domain (ECD) a 21 aa transmembrane domain and a 263 aa cytoplasmic domain. The ECD shows 4 conserved cysteine residues, a fibronectin type III domain, and a WSXWS motif; the cytoplasmin region possesses a Box1 motif, a kinase domain, and several sites for tyrosine phosphorylation (4, 5). One such site, pY502, mediates STAT binding (1, 2). The rat IL‑21 R ECD shares 70%, 91%, 66%, 63% and 58% aa identity with human, mouse, equine, canine and bovine IL-21 R, respectively. One potential 445 aa isoform is reported that contains an alternative start site at Met77. If expressed, it would lack three of the four conserved ECD cysteines seen in full-length rat IL-21 R (8). IL-21 R is expressed mainly on B cells (highest on mature, activated, follicular and germinal center B cells), NK cells, and activated T cells, but is also found on dendritic cells, alternatively activated macrophages, intestinal lamina propria fibroblasts and epithelial cells, and keratinocytes (1, 3 ‑ 5). Both IL-21 and IL-4 are necessary for efficient B cell IgG1 production and normal germinal center architecture (9). IL-21 engagement of the IL‑21 receptor on B cells induces Blimp-1 (which mediates plasma cell differentiation), and is important for memory responses (1, 10, 11). IL‑21 R engagement on mouse NK cells enhances their cytotoxic activity and IFN-gamma production (4, 12). IL‑21 R engagement on CD8⁺ T cells aids control of viral infection and tumor growth; IL‑21 R is also necessary for sufficient numbers of regulatory T cells to combat chronic inflammation (1, 13, 14). IL‑21 R expression is often up‑regulated in allergic skin inflammation, systemic lupus erythematosus and diffuse large B cell lymphoma (DLBCL) (1, 2, 15, 16).

Related Research Areas

• B Cell Markers
• Common gamma Chain Receptor Family
• Cytokines and Receptors in Tfh Cell Differentiation and Function
• Isolation, Culture, and Identification of Natural Killer Cells
• Natural Killer T (NKT) Cells
• Receptors in the Jak/STAT Pathway
• Th17 Cells
• Th22 Cells