Recombinant Human IL-21R Fc Chimera Avi-tag Protein, CF

Recombinant Human IL-21R Fc Chimera Avi-tag 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

Interleukin-21 Receptor (IL-21 R) is a type I transmembrane glycoprotein within the class I cytokine receptor family (1). IL-21 R associates with the common  gamma  chain ( gamma _c) which is also a component of the receptors for IL-2, IL-4, IL-7, IL-9, IL-13, and IL-15 (2, 3). Mature human IL-21 R consists of a 213 amino acid (aa) extracellular domain (ECD) with 4 conserved cysteine residues, a fibronectin type III domain, and a WSxWS motif, followed by a 21 aa transmembrane domain and a 253 aa cytoplasmic domain with a Box 1 motif, a kinase domain, and several sites for tyrosine phosphorylation (4, 5). Within the ECD, human IL-21 R shares 69% aa identity with mouse and rat IL-21 R, respectively. 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, 4, 5). Both IL-21 and IL-4 are necessary for efficient B cell IgG1 production and normal germinal center architecture (6). B cell IL-21 R engagement induces Blimp-1 (which mediates plasma cell differentiation) and is important for memory responses (7, 8). IL-21 R engagement enhances NK cell mediated cytotoxic activity and IFN-gamma production (4, 9), control of viral infection and tumor growth by CD8⁺ T cells (10), development of regulatory T cells (11), IL-23 responsiveness of encephalitogenic Th17 cells (12), but suppresses the accumulation of IL-17 secreting gamma δ T cells in the airway (13). IL-21 R expression is often upregulated in allergic skin inflammation, systemic lupus erythematosus and diffuse large B cell lymphoma (DLBCL) (14, 15). Our Avi-tag Biotinylated human IL-21R Fc Chimera features biotinylation at a single site contained within the Avi-tag, a unique 15 amino acid peptide. Protein orientation will be uniform when bound to streptavidin-coated surface due to the precise control of biotinylation and the rest of the protein is unchanged so there is no interference in the protein's bioactivity.

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