FCGR4

Fcgr4 is a receptor for the Fc portion of immunoglobulin G, and it is involved in the removal of antigen-antibody complexes from the circulation, as well as other other antibody-dependent responses. This gene (FCGR3A) is highly similar to another nearby gene (FCGR3B) located on chromosome 1. The receptor encoded by this gene is expressed on natural killer (NK) cells as an integral membrane glycoprotein anchored through a transmembrane peptide, whereas FCGR3B is expressed on polymorphonuclear neutrophils (PMN) where the receptor is anchored through a phosphatidylinositol (PI) linkage. Mutations in this gene have been linked to susceptibility to recurrent viral infections, susceptibility to systemic lupus erythematosus, and alloimmune neonatal neutropenia.

Fc receptor, IgG, low affinity IV

Fcrl3; CD16-2; FcgRIV; Fcgr3a; FcgammaRIV; 4833442P21Rik

Receptor for the Fc region of immunoglobulin gamma (PubMed:16039578).

Also acts as a receptor for the Fc region of immunoglobulin epsilon (PubMed:17558411, PubMed:18949059).

Binds with intermediate affinity to both IgG2a and IgG2b (PubMed:16039578, PubMed:17558411, PubMed:19795417).

Can bind to IgG2a and IgG2b monomers (PubMed:18949059).

Does not display binding to IgG1 or IgG3 (PubMed:16039578).

Mediates neutrophil activation by IgG complexes redundantly with Fcgr3 (PubMed:18097064).

Plays a role in promoting bone resorption by enhancing osteoclast differentiation following binding to IgG2a (PubMed:25824719).

Binds with low affinity to both the a and b allotypes of IgE (PubMed:18949059).

Has also been shown to bind to IgE allotype a only but not to allotype b (PubMed:17558411).

Binds aggregated IgE but not the monomeric form and bound monomeric IgG is readily displaced by IgE complexes (PubMed:18949059).

Binding to IgE promotes macrophage-mediated phagocytosis, antigen presentation to T cells, production of proinflammatory cytokines and the late phase of cutaneous allergic reactions (PubMed:17558411, PubMed:18949059).

Cell surface receptor signaling pathway Source: GO_Central
Cellular response to lipopolysaccharide Source: MGI
Neutrophil activation Source: UniProtKB
Positive regulation of bone resorption Source: UniProtKB
Regulation of immune response Source: GO_Central
Regulation of sensory perception of pain Source: MGI
Wound healing Source: Ensembl

Cell membrane. Cell surface expression is dependent on the presence of the Fc receptor gamma chain Fcerg.

Extracellular: 21-203
Helical: 204-224
Cytoplasmic: 225-249

N-glycosylated.
Phosphorylated following receptor ligation.