Fc Receptor, IgG, Low Affinity IV Proteine

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). {ECO:0000269|PubMed:16039578, ECO:0000269|PubMed:17558411, ECO:0000269|PubMed:18097064, ECO:0000269|PubMed:18949059, ECO:0000269|PubMed:19795417, ECO:0000269|PubMed:25824719}.