Recombinant Cynomolgus Monkey FCAR/CD89 Protein, CF

When Human IgA iscoated at 5 µg/mL (100 μL/well), Recombinant Cynomolgus MonkeyFCAR/CD89 (Catalog # 9516-FA) binds with an ED50 of 0.5-2.5 μg/mL.

• Reactivity: Pm-Cm
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Cynomolgus Monkey FCAR/CD89 Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA. When Human IgA is immobilized at 5 μg/mL, 100 μL/well, the concentration of Recombinant Cynomolgus Monkey FCAR/CD89 that produces 50% of the optimal binding response is 0.250-2.50 μg/mL.
• Source: Mouse myeloma cell line, NS0-derived cynomolgus monkey FCAR/CD89 protein
  Gln22-Asn227, with a C-terminal 6-His tag
• Accession #: XP_005590398.1
• N-terminal Sequence: No reults obtained. Gln 22 inferred from enzymatic pyroglutamate treatment revealing Glu23
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 24 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 33-70 kDa, under reducing conditions.

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 200 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Cynomolgus Monkey FCAR/CD89 Protein, CF

• CD89 antigen
• CD89
• CD89IgA Fc receptor
• Fc alpha receptor
• Fc fragment of IgA, receptor for
• FCAR
• immunoglobulin alpha Fc receptor

Background

FCAR, also called Fc alpha RI or CD89, is a variably glycosylated 50-100 kDa myeloid-specific type I transmembrane (TM) Fc receptor for IgA and is a member of the multi-chain immune recognition receptor (MIRR) family (1-3). Cynomolgus FCAR is predicted to contain a 21 amino acid (aa) signal sequence and 206 aa extracellular (ECD), 19 aa TM and 41 aa cytoplasmic domains (4). The Arg230 within the TM domain of human FCAR supports interaction with the ITAM-containing signaling subunit, FcR gamma, which contains a TM Asp (5-7). Two ECD C2-type Ig-like domains (EC1 and 2) are oriented at right angles (8). Up to two molecules of FCAR can bind one molecule of serum IgA via EC1 (8). Many human FCAR splice variants have been reported, but only two have been identified as proteins (9, 10). The a.2 form, which lacks 22 aa just prior to the TM domain, is exclusively expressed in alveolar macrophages. The a.3 form lacks EC2. FCAR binds monomeric, polymeric and secretory IgA, but does not mediate the barrier function of secretory IgA in mucosal epithelium (1-3). Shedding and circulation of polymeric IgA/FCAR immune complexes has been reported (11). Circulating neutrophils, eosinophils, and monocytes express FCAR (12). Tissue expression of FCAR is mainly from neutrophils; FCAR is down-regulated as monocytes differentiate to tissue macrophages (12). On neutrophils, a significant amount of FCAR lacks FcR gamma, but can still be endocytosed to early endosomes and recycled to the cell surface (5). Binding of serum IgA to FCAR is transient and anti-inflammatory, inhibiting IgG or IgE-induced degranulation (6). Sustained aggregation of FCAR results in inflammatory responses (6). FcR gamma signaling is required for these and for transport to late endosomes (5-7). Within ECD, Cynomolgus FCAR shows 83% aa identity with human FCAR. No ortholog occurs in mouse. FCAR structure resembles the KIR/ILT/LIR/MIR family more than other IgA receptors, including pIgR, Fc alpha /μR, asialoglycoprotein receptor (ASGR1) and transferrin receptor (TfR) (1-3).

1. Wines, B. D. and P. M. Hogarth (2006) Tissue Antigens 68:103.
2. Otten, M. A. and M. van Egmon (2004) Immunol. Lett. 92:23.
3. Montiero, R. C. and J. G. J. van de Winkel (2003) Annu. Rev. Immunol. 21:177.
4. Maliszewski, C. R. et al. (1990) J. Exp. Med. 172:1665.
5. Launay, P. et al. (1999) J. Biol. Chem. 274:7216.
6. Pasquier, B. et al. (2005) Immunity 22:31.
7. Shen, L. et al. (2001) Blood 97:205.
8. Herr, Y. et al. (2003) Nature 423:614.
9. Patry, C. et al. (1996) J. Immunol. 156:4442.
10. Togo, S. et al. (2003) FEBS Lett. 535:205.
11. van der Boog, P. J. M. et al. (2002) J. Immunol. 168:1252.
12. Hamre, R. et al. (2003) Scand. J. Immunol. 57:506.

Bioinformatics

• Uniprot:
  • XP_005590398.1()