• Purity

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

• Endotoxin Level

  <0.01 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to bind human IgG with an estimated K    _D <80 nM.  

• Source

  Mouse myeloma cell line, NS0-derived Leu20-Asp395, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Leu20

• Predicted Molecular Mass

  41.9 kDa

• SDS-PAGE

  60-68 kDa, reducing conditions

Background: FCRL2/FcRH2

Fc receptor-like 2 (FCRL2), also known as FcRH2 and IRTA4, belongs to the family of glycoprotein homologs of classical immunoglobulin (Ig) Fc receptors. In human, the type I transmembrane FCRL protein family contains from three to nine immunoglobulin-like domains (1, 2). Mature human FcRH2 consists of a 382 amino acid (aa) extracellular domain (ECD) with four Ig-like C2-set domains, a 21 aa transmembrane segment, and an 86 aa cytoplasmic domain with one ITAM-like, and two ITIM-like motifs (3 - 5). Alternate splicing of human FCRL2 may generate isoforms with N-terminal, internal, or C-terminal deletions (4, 5). The gene for FcRH2 maps to the human Iq21-23 locus which is a hotspot for chromosomal translocation events associated with B cell malignancies (3, 6). Although there are several Fc receptor-like genes in the mouse, none of these is a clear ortholog to human FCRL2 (7). FCRL proteins are differentially expressed among B cells (2). FCRL2 is preferentially expressed on naïve and CD27⁺ memory B cells within the spleen, lymph nodes, tonsils, and peripheral blood (3, 4, 8, 9). It is also expressed on most B cells in B cell chronic lymphocytic leukemia (B-CLL) patients (10). FCRL2 upregulation is associated with mutation of the immunoglobulin heavy chain variable (IGHV) and less aggressive forms of B-CLL (9, 11).

• References:

1. Maltais, L.J. et al. (2006) Nat. Immunol. 7:431.

2. Davis, R.S. et al. (2007) Annu. Rev. Immunol. 25:525.

3. Miller, I. et al. (2002) Blood 99:2662.

4. Davis, R.S. et al. (2001) Proc. Natl. Acad. Sci. 98:9772.

5. Xu, M.J. et al. (2001) Biochem. Biophys. Res. Commun. 280:768.

6. Hatzivassiliou, G. et al. (2001) Immunity 14:277.

7. Davis, R.S. et al. (2004) Int. Immunol. 16:1343.

8. Polson, A.G. et al. (2006) Int. Immunol. 18:1363.

9. Huttmann, A. et al. (2006) Leukemia 20:1774.

10. Kazemi, T. et al. (2008) Int. J. Cancer 123:2113.

11. Li, F.J. et al. (2008) Blood 112:179.

• Long Name:

  Fc Receptor-like 2

• Entrez Gene IDs:

  79368 (Human)

• Alternate Names:

  CD307b antigen; CD307b; Fc receptor homolog 2; Fc receptor-like 2; FcRH2; FCRH2SPAP1B; FCRL2; FcR-like protein 2; IFGP family protein 4; IFGP4; Immunoglobulin receptor translocation-associated protein 4; immunoglobulin superfamily Fc receptor, gp42; IRTA4; IRTA4SPAP1C; SH2 domain containing phosphatase anchor protein 1; SH2 domain-containing phosphatase anchor protein 1Fc receptor-like protein 2; SPAP1; SPAP1A; SPAP1immune receptor translocation-associated protein 4