• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to inhibit IL-21-dependent proliferation of N1186 human T cells Parrish-Novak, J.     et al. (2000) Nature     408:57. The ED    ₅₀ for this effect is 0.75‑3 µg/mL in the presence of 100 ng/mL of recombinant mouse IL-21.

• Source

  Mouse myeloma cell line, NS0-derived

  Mouse IL-21 R Subunit (Cys20 - Pro236) Accession # Q9JHX3	IEGRMD	Human IgG1 (Pro100 - Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Cys20

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  51.5 kDa (monomer)

• SDS-PAGE

  70-80 kDa, reducing conditions

Background: IL-21 R

IL-21 R (interleukin-21 receptor) is a type I transmembrane glycoprotein within 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, IL-13 and IL-15 receptors, is required for signaling (6, 7). Mouse IL-21 R cDNA encodes 521 amino acid (aa) including a 19 aa signal peptide, a 218 aa extracellular domain (ECD) with 4 conserved cysteine residues, a fibronectin type III domain, and a WSXWS motif, a 21 aa transmembrane domain and a 271 aa cytoplasmic domain with a Box 1 motif, a kinase domain, and several sites for tyrosine phosphorylation (4, 5). One such site, pY510, mediates STAT binding (1, 2). The mouse IL‑21 R ECD shares 69%, 91%, 65%, 63% and 58% aa identity with human, rat, equine, canine and bovine IL-21 R, respectively. One potential 447 aa isoform, with an alternate start site at aa 83, lacks the four conserved ECD cysteines. 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 (8). B cell IL‑21 R engagement induces Blimp-1 (which mediates plasma cell differentiation), and is important for memory responses (1, 9, 10).  IL-21 R engagement on mouse NK cells enhances their cytotoxic activity and IFN-gamma production (4, 11). 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, 12, 13). IL‑21 R expression is often up‑regulated in allergic skin inflammation, systemic lupus erythematosus and diffuse large B cell lymphoma (DLBCL) (1, 2, 14, 15).

• References:

1. Leonard, W.J. et al. (2008) J. Leukoc. Biol. 84:348.

2. Konforte, D. et al. (2009) J. Immunol. 182:1791.

3. Monteleone, G. et al., 2009, Cytokine Growth Factor Rev. 20:185.

4. Parrish-Novak, et al. (2000) Nature 408:57.

5. Ozaki, K. et al. (2000) Proc. Natl. Acad. Sci. USA 97:11439.

6. Asao, H. et al. (2001) J. Immunol. 167:1.

7. Habib, T. et al. (2002) Biochemistry 41:8725.

8. Ozaki, K. et al. (2002) Science 298:1630.

9. Rankin, A.L. et al. (2011) J. Immunol. 186:667.

10. King, I.L. et al. (2010) J. Immunol. 185:6138.

11. Kasaian, M.T. et al. (2002) Immunity 16:559.

12. Frohlich, A. et al. (2009 Science 324:1576.

13. Tortola, L. et al. (2010) Blood 116:5200.

14. Jin, H. et al. (2009) J. Clin. Invest. 119:47.

15. Sarosiek, K.A. et al. (2010) Blood 115:570.

• Long Name:

  Interleukin 21 Receptor

• Entrez Gene IDs:

  50615 (Human); 60504 (Mouse)

• Alternate Names:

  CD360 antigen; CD360; IL-21 R; IL-21 receptor; IL21R; IL-21R; interleukin 21 receptor; interleukin-21 receptor; MGC10967; NILR; Novel interleukin receptor