Recombinant Human Fc epsilon RI alpha Protein, CF

When Recombinant Human Fc epsilon RI alpha (6678-FC) is immobilized at 0.1 μg/mL (100 μL/well), the concentration of human IgE that produces 50% of the optimal binding response is found to be approximately 0.05­-0.2 μg/mL.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human Fc epsilon RI alpha Protein, CF Summary

• Details of Functionality: Measured by its binding ability in a functional ELISA.

  When Recombinant Human Fc epsilon RI alpha is immobilized at 0.1 μg/mL (100 μL/well), the concentration of human IgE that produces 50% of the optimal binding response is found to be approximately 0.0200-0.200 μg/mL.

• Source: Mouse myeloma cell line, NS0-derived human Fc epsilon RI alpha protein
  Val26-Gln205, with a C-terminal 6-His tag
• Accession #: NP_001992
• N-terminal Sequence: Val26
• Protein/Peptide Type: Recombinant Proteins
• Gene: FCER1A
• 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: 21.9 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: 45-58 kDa, 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.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 100 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 Human Fc epsilon RI alpha Protein, CF

• Fc epsilon RI alpha
• Fc epsilon RI alpha-chain
• Fc fragment of IgE receptor Ia
• Fc fragment of IgE, high affinity I, receptor for; alpha polypeptide
• Fc IgE receptor, alpha polypeptide
• FCE1A
• Fc-epsilon RI-alpha
• FcepsilonRI alpha chain
• FcepsilonRIalpha
• FCER1A
• FcERI
• FceRIa
• high affinity immunoglobulin epsilon receptor alpha-subunit
• high affinity immunoglobulin epsilon receptor subunit alpha
• igE Fc receptor subunit alpha
• immunoglobulin E receptor, high-affinity, of mast cells, alpha polypeptide

Background

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).

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.

Publications for Fc epsilon RI alpha (6678-FC)(1)

Publication using 6678-FC

• M Metz, G Sussman, R Gagnon, P Staubach, T Tanus, WH Yang, JJ Lim, HJ Clarke, J Galanter, LW Chinn, T Chu, A Teterina, T Burgess, DJ Haddon, TT Lu, M Maurer Fenebrutinib in H1 antihistamine-refractory chronic spontaneous urticaria: a randomized phase 2 trial Nature Medicine, 2021-11-08;27(11):1961-1969. 2021-11-08 [PMID: 34750553] (Bioassay, Human)

Bioinformatics

• Gene Symbol: FCER1A
• Uniprot:
  • NP_001992()