title: A macrophage Fc gamma receptor and the mast cell receptor for IgE share an identical subunit.
abstract: Fc receptors for immunoglobulins are found on many immune cells and trigger essential functions of the immune defence system. With the exception of the high-affinity receptor for immunoglobulin E (Fc epsilon RI), these receptors were thought to consist of single polypeptides. Fc epsilon RI is a tetrameric complex of one alpha-subunit, one beta-subunit and two gamma-subunits. Here we report the cloning of a polypeptide identical to the gamma-chains of Fc epsilon RI, from mouse macrophages that do not express this receptor. Biosynthetic labelling and gene transfer together show that these gamma-chains associate with one of the macrophage receptors (Fc gamma RIIa). The human homologue, Fc gamma RIII (CD16), from natural killer cells is also expected to associate with gamma-chains. It is possible that these gamma-chains and the homologous zeta-chains of the T-cell antigen receptor belong to a new family of related proteins which share a common role in the signal transducing pathway.
authors.affiliation: Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland 20892.
authors.forename: C
authors.initials: C
authors.lastname: Ra
authors.forename: M H
authors.initials: MH
authors.lastname: Jouvin
authors.forename: U
authors.initials: U
authors.lastname: Blank
authors.forename: J P
authors.initials: JP
authors.lastname: Kinet
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D003001:Cloning, Molecular; D015870:Gene Expression; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D011961:Receptors, Fc / Q000235:genetics / Q000276:immunology*; D017455:Receptors, IgE; D017452:Receptors, IgG
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017455:Receptors, IgE; D017452:Receptors, IgG; D007073:Immunoglobulin E