CD16b Antibody – Mouse Monoclonal

The protein encoded by this gene is a low affinity receptor for the Fc region of gamma immunoglobulins (IgG). The encoded protein acts as a monomer and can bind either monomeric or aggregated IgG. This gene may function to capture immune complexes in the peripheral circulation. Several transcript variants encoding different isoforms have been found for this gene. A highly-similar gene encoding a related protein is also found on chromosome 1. [provided by RefSeq, Aug 2012]

Function: Receptor for the Fc region of immunoglobulins gamma. Low affinity receptor. Binds complexed or aggregated IgG and also monomeric IgG. Contrary to III-A, is not capable to mediate antibody-dependent cytotoxicity and phagocytosis. May serve as a trap for immune complexes in the peripheral circulation which does not activate neutrophils.

Subunit structure: Monomer. Interacts with INPP5D/SHIP1

By similarity.

Subcellular location: Cell membrane; Lipid-anchor › GPI-anchor. Secreted. Note: Secreted after cleavage.

Tissue specificity: Expressed specifically by polymorphonuclear leukocytes (neutrophils). Also expressed by stimulated eosinophils.

Post-translational modification: Glycosylated. Glycosylation plays an inhibitory role in the interaction with IgG3.The soluble form is produced by a proteolytic cleavage.

Polymorphism: There are three allelic forms of FCGR3B: FCGR3B*01 (NA-1), FCGR3B*02 (HNA-1b, NA-2) (shown here) and SH. FCGR3B*01 and FCGR3B*02 are detectable with antibodies against the biallelic neutrophil-specific antigen system NA. The more active FCGR3B*01 allele has been associated with severe renal disease in certain systemic vasculitides.

Miscellaneous: Encoded by one of two nearly indentical genes: FCGR3A and FCGR3B (Shown here) which are expressed in a tissue-specific manner. The 'Phe-203' in FCGR3A determines the transmembrane domains whereas the Ser-203 in FCGR3B determines the GPI-anchoring.

Sequence similarities: Contains 2 Ig-like C2-type (immunoglobulin-like) domains.