• 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 ED₅₀ for this effect is 1-5 μg/mL in the presence of 50 ng/mL of recombinant mouse IL-21.

• Source

  Mouse myeloma cell line, NS0-derived

  Rat IL-21 R (Met1 - Pro236) Accession # Q5EBB1	IEGRMDP	Mouse IgG2A (Glu98 - Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Cys20

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  52.2 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 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).

• 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. Genbank Accession # EDM17511.

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

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

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

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

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

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

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

16. 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