Fine structure analysis of interaction of FcεRI with IgE

Abstract

The high affinity receptor for IgE (FcεRI) plays an integral role in triggering IgE-mediated hypersensitivity reactions. The IgE-interactive site of human FcεRI has previously been broadly mapped to several large regions in the second extracellular domain (D2) of the α-subunit (FcεRIα). In this study, the IgE binding site of human FcεRIα has been further localized to subregions of D2, and key residues putatively involved in the interaction with IgE have been identified. Chimeric receptors generated between FcεRIα and the functionally distinct but structurally homologous low affinity receptor for IgG (FcγRIIa) have been used to localize two IgE binding regions of FcεRIα to amino acid segments..