|CD16b||FCγRIIIB(Fc fragment of IgG, low affinity IIIb receptor), FCRIIIB|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
|50 / 50|
60 / 60
|CD16b is expressed on the transmembrane form in humans on NK cells, macrophages and mast cells, while the GPI-anchored form is expressed on neutrophils and can be induced in eosinophils by IFN-γ. In the mouse no GPI-anchored form of CD16b has been identified and the transmembrane form is expressed on macrophages, NK cells, neutrophils, myeloid precursors and the majority of early CD4-CD8-TCR- fetal thymocytes.|
|MOLECULAR FAMILY NAME: Belongs to the immunoglobulin supergene family.|
CD16b is GPI-anchored glycoprotein. It contains an extracellular domain which contains 2 Ig-like-C2-type domains but lacks a transmembrane domain and cytoplasmic domain.
POST-TRANSCRIPTIONAL MODIFICATION: No information.
POST-TRANSLATIONAL MODIFICATION: No information.
|LIGANDS AND MOLECULES ASSOCIATED WITH CD16b|
The transmembrane form is non-covalently associated with the FceRI g chain or the TCR z chain. CD16b on mast cells is also associated with the b chain of the FceRI.
|CD16b is a low affinity receptor and binds the constant region of IgG1 and IgG3. In contrast to CD16a, the GPI-anchored form on neutrophils binds to ligands but is unable to induce any intrinsic signaling or functional effect but is capable of inducing antibody-dependent cellular cytotoxicity (ADCC) or erythrocytes and phagocytosis by neutrophils. Targeted disruption of the mouse FceRI common to CD16b and FceRI results in immunocompromised mice. |
BIOCHEMICAL ACTIVITY: No information.
DISEASE RELEVANCE AND FUNCTION OF CD16b IN INTACT ANIMAL
CD16b is expressed on human peripheral blood eosinophils which increases in allergic conditions. CD16b is a marker in leukemia and HIV. It is used to purify bone marrow and germinal subsets. CD16b alleles can be used as risk markers for systemic lupus erythematosus (SLE). This disease is characterized by the presence of circulating immune complexes and a susceptibility to bacterial infections.
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD16b: No information.
SUBSTRATES: No information.
ENZYMES WHICH MODIFY CD16b: No information.
Database accession numbers
Revised June 25, 2008