Fc Fragment Of IgG Low Affinity IIb, Receptor (FcgR2B)

FCGR2B is a low affinity receptor for the Fc region of immunoglobulin gamma complexes. The encoded protein is involved in the phagocytosis of immune complexes and in the regulation of antibody production by B-cells. Variations in this gene may increase susceptibilty to systemic lupus erythematosus (SLE). Several transcript variants encoding different isoforms have been found for this gene.Sequence analysis predicted that the 291-amino acid protein has a 42-residue signal sequence; 2 extracellular Ig-like domains with 3 potential N-glycosylation sites; a transmembrane region; and a 43-amino acid cytoplasmic region. Immunofluorescence microscopy demonstrated surface expression of FCGR2B, and prolonged incubation with ligand led to endocytosis.