title: The CD19-CR2-TAPA-1 complex, CD45 and signaling by the antigen receptor of B lymphocytes.
abstract: A paradigm describing the response of T lymphocytes to antigen holds that signals from antigen receptors must be modulated by non-antigen-specific, accessory membrane proteins for an appropriate cellular response to occur, such as differentiation, activation and tolerance. Recent studies suggest that this paradigm applies also to B lymphocytes. Signaling through membrane IgM in these cells requires CD45, a phosphotyrosine phosphatase, and is amplified by a complex containing CD19, complement receptor 2 (CD21), and TAPA-1, which recruits the intracellular enzyme, phosphatidylinositol 3-kinase.
authors.affiliation: University of Cambridge School of Clinical Medicine, UK.
authors.forename: D T
authors.initials: DT
authors.lastname: Fearon
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology*; D000954:Antigens, Surface / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology*; D006168:Guinea Pigs; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000502:physiology*; D008024:Ligands; D008213:Lymphocyte Activation / Q000502:physiology*; D046911:Macromolecular Substances; D008565:Membrane Proteins; D051379:Mice; D008954:Models, Biological; D005810:Multigene Family; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000502:physiology; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D017464:Receptors, Complement 3d / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D060225:Tetraspanin 28
chemical_list: D015703:Antigens, CD; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; C554798:CD81 protein, human; C554799:Cd81 protein, mouse; D007075:Immunoglobulin M; D008024:Ligands; D046911:Macromolecular Substances; D008565:Membrane Proteins; D011947:Receptors, Antigen, B-Cell; D017464:Receptors, Complement 3d; D060225:Tetraspanin 28; D011505:Protein-Tyrosine Kinases; D017493:Leukocyte Common Antigens