title: Cytoplasmic domain heterogeneity and functions of IgG Fc receptors in B lymphocytes.
abstract: B lymphocytes and macrophages express closely related immunoglobulin G (IgG) Fc receptors (Fc gamma RII) that differ only in the structures of their cytoplasmic domains. Because of cell type-specific alternative messenger RNA splicing, B-cell Fc gamma RII contains an insertion of 47 amino acids that participates in determining receptor function in these cells. Transfection of an Fc gamma RII-negative B-cell line with complementary DNA's encoding the two splice products and various receptor mutants indicated that the insertion was responsible for preventing both Fc gamma RII-mediated endocytosis and Fc gamma RII-mediated antigen presentation. The insertion was not required for Fc gamma RII to modulate surface immunoglobulin-triggered B-cell activation. Instead, regulation of activation involved a region of the cytoplasmic domain common to both the lymphocyte and macrophage receptor isoforms. In contrast, the insertion did contribute to the formation of caps in response to receptor cross-linking, consistent with suggestions that the lymphocyte but not macrophage form of the receptor can associate with the detergent-insoluble cytoskeleton.
authors.affiliation: Laboratoire d'Immunologie Cellulaire et Clinique, INSERM U 255, Institut Curie, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Amigorena
authors.forename: C
authors.initials: C
authors.lastname: Bonnerot
authors.forename: J R
authors.initials: JR
authors.lastname: Drake
authors.forename: D
authors.initials: D
authors.lastname: Choquet
authors.forename: W
authors.initials: W
authors.lastname: Hunziker
authors.forename: J G
authors.initials: JG
authors.lastname: Guillet
authors.forename: P
authors.initials: P
authors.lastname: Webster
authors.forename: C
authors.initials: C
authors.lastname: Sautes
authors.forename: I
authors.initials: I
authors.lastname: Mellman
authors.forename: W H
authors.initials: WH
authors.lastname: Fridman
mesh_terms: D000595:Amino Acid Sequence; D000936:Antigen-Antibody Complex / Q000378:metabolism; D000937:Antigen-Antibody Reactions / Q000235:genetics / Q000276:immunology; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology*; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D004268:DNA-Binding Proteins; D004306:Dose-Response Relationship, Immunologic; D004705:Endocytosis / Q000235:genetics / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008213:Lymphocyte Activation / Q000276:immunology; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D011961:Receptors, Fc / Q000235:genetics / Q000276:immunology*; D017452:Receptors, IgG; D012097:Repressor Proteins / Q000494:pharmacology; D014157:Transcription Factors / Q000494:pharmacology; D014162:Transfection; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D000936:Antigen-Antibody Complex; D015703:Antigens, CD; D000943:Antigens, Differentiation; D004268:DNA-Binding Proteins; D011961:Receptors, Fc; D017452:Receptors, IgG; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D002118:Calcium