• Species Reactivity

  Human

• Specificity

  Detects human Fc epsilon RI alpha in direct ELISAs.

• Source

  Monoclonal Mouse IgG2b Clone # 773704

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human Fc epsilon RI alpha    
  Val26-Gln205    
  Accession # P12319

• Formulation

  Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

• Label

  Alexa Fluor 700

Applications

• 
  

  Recommended    
  Concentration

  Sample

• Flow Cytometry

  0.25-1 µg/10    ⁶ cells

  Human peripheral blood cells

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: Fc epsilon RI alpha

The alpha subunit of the high affinity IgE receptor (Fc epsilon  RI alpha or Fc epsilon RIA) is an IgE‑binding type I transmembrane glycoprotein of the multichain immune recognition (MIRR) family (1, 2). The receptor, Fc epsilon  RI, is a tetrameric complex of one alpha, one beta and two gamma subunits ( alpha beta gamma ₂) on mast cells and basophils (1). An alternate trimeric form ( alpha gamma ₂) is expressed on human, but not rodent, mast cells, basophils, eosinophils and professional antigen presenting cells (3). While the gamma subunit is essential for expression of Fc epsilon  RI alpha on the cell surface and for cell signaling, the beta subunit, when present, increases the halflife of the Fc epsilon  RI complex on the cell surface (3, 4). An isoform of the beta subunit, beta T, blocks processing of the alpha subunit and its cell surface expression (2, 3, 5). Human Fc epsilon  RI alpha cDNA encodes 257 amino acids (aa) including a 25 aa signal sequence, a 180 aa extracellular domain containing two Ig‑like domains that bind IgE and an endoplasmic reticulum retention motif, a 21 aa transmembrane domain with a charged amino acid (Asp219) that contributes to intracellular transport, and a 32 aa cytoplasmic sequence (1, 3, 6). Human Fc epsilon  RI alpha shares 50‑62% aa sequence identity with mouse, rat, equine, ovine, bovine, porcine and canine Fc epsilon  RI alpha. Binding of IgE alone increases surface expression of Fc epsilon  RI, while crosslinking of IgE/Fc epsilon  RI complexes by IgE ligands (allergens) initiates receptor internalization and signaling (2, 4, 5). Mast cell and basophil activation by IgE/Fc epsilon  RI crosslinking causes degranulation, releasing histamine, leukotrienes, prostaglandins, and other mediators of immediate‑type and late‑phase allergic reactions. Circulating autoantibodies that crosslink Fc epsilon  RI alpha are often found in patients with chronic urticaria (7). Fc epsilon  RI on human antigen presenting cells mediates uptake and processing of allergens for presentation by class II MHC (2, 3). Fc epsilon  RI expression on human DC and Langerhans cells is up‑regulated during allergic reactions (atopy) and correlates with serum IgE concentration (3).

• References:

1. Shimizu, A. et al. (1988) Proc. Natl. Acad. Sci. USA 85:1907.

2. Abramson, J. and I. Pecht (2007) Immunol. Rev. 217:231.

3. Kraft, S. and J-P. Kinet (2007) Nat. Rev. Immunol. 7:365.

4. Yamasaki, S. and T. Saito (2008) J. Pharmacol. Sci. 106:336.

5. Brenzovich, J. et al. (2009) J. Leukoc. Biol. 86:1351.

6. Cauvi, D.M. et al. (2006) J. Biol. Chem. 281:10448.

7. Kikuchi, Y. et al. (2001) J. Allergy Clin. Immunol. 107:1056.

• Long Name:

  Fc epsilon Receptor I alpha

• Entrez Gene IDs:

  2205 (Human); 14125 (Mouse); 25047 (Rat)

• Alternate Names:

  Fc epsilon RI alpha; FCE1A; FCER1A; FcERI; FceRIa