FITC Mouse Anti-Human FcεRIα Antibody (S-2866)

FcεRIα is a single-pass transmembrane glycoprotein of the immunoglobulin superfamily that forms the ligand-binding backbone of the tetrameric high-affinity IgE receptor (FcεRI) expressed on mast cells and basophils; its extracellular region folds into two Ig-like domains that clamp the Fc portion of IgE with picomolar affinity, positioning the constant heavy-chain ε2-3 interface for optimal recognition, while a short cytoplasmic tail lacks signaling motifs but critically nucleates the entire receptor complex by juxtamembrane interactions with the four-helix FcεRIβ subunit and the disulfide-linked FcRγ homodimer, thereby dictating the architecture of the transmembrane three-helix bundle that propagates ITAM-based phosphorylation cascades upon IgE/allergen crosslinking and drives immediate degranulation, cytokine release and the clinical manifestations of type I hypersensitivity.