Recombinant Human FCER1G protein

The Fc epsilon receptor I gamma subunit (FCER1G) is a critical component of high-affinity immunoglobulin epsilon (IgE) receptors, primarily known for its role in allergic responses and immune regulation. Encoded by the FCER1G gene in humans, this protein forms a disulfide-linked homodimer that associates with ligand-binding α-subunits (e.g., FCER1A) and β-subunits in mast cells and basophils. As a common signaling module, it also partners with other Fc receptors (FcγRI, FcαRI) to mediate cell activation through immunoreceptor tyrosine-based activation motif (ITAM) domains.

Structurally, FCER1G contains an extracellular domain, transmembrane region, and cytoplasmic tail with conserved ITAM sequences essential for signal transduction. Upon IgE-antigen crosslinking, phosphorylated ITAMs recruit tyrosine kinases (e.g., Syk), triggering downstream pathways that lead to inflammatory mediator release. This mechanism underlies immediate hypersensitivity reactions in conditions like asthma and anaphylaxis.

Recombinant FCER1G protein is produced using mammalian or insect expression systems to ensure proper post-translational modifications. Purification typically involves affinity chromatography with tags like His or Fc fusions. The recombinant form retains functional ITAM domains while eliminating confounding variables from native cell environments, making it valuable for studying IgE receptor assembly, signal transduction mechanisms, and cross-talk between immune receptors.

Researchers use FCER1G recombinant proteins in vitro to investigate allergic disease pathophysiology, screen therapeutic inhibitors targeting IgE signaling, and model immune receptor interactions. Its applications extend to studying rare FCER1G-linked immunodeficiencies and developing diagnostic tools for hypersensitivity disorders. Mutant variants are also engineered to dissect structure-function relationships, particularly ITAM phosphorylation dynamics and adaptor protein recruitment patterns.