title: Gamma-chain dependent recruitment of tyrosine kinases to membrane rafts by the human IgA receptor Fc alpha R.
abstract: We show that the human IgA receptor, Fc alpha R, redistributes to plasma membrane rafts after cross-linking and that tyrosine kinases are relocated to these sites following Fc alpha R capping. We demonstrate by confocal microscopy that Fc alpha R caps in membrane rafts by a gamma-chain-independent mechanism but that gamma-chain expression is necessary for Lyn redistribution. Immunoblotting of rafts isolated by sucrose density gradient centrifugation demonstrated recruitment of gamma-chain and phosphorylated tyrosine kinases Lyn and Bruton's tyrosine kinase to membrane rafts after Fc alpha R cross-linking. Time-dependent differences in Lyn phosphorylation and Bruton's tyrosine kinase distribution were observed between cells expressing Fc alpha R plus gamma-chain and cells expressing Fc alpha R only. This study defines early Fc alpha R-triggered membrane dynamics that take place before Fc alpha R internalization.
authors.affiliation: Department of Microbiology, Dartmouth Medical School, Lebanon, NH 03756, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Lang
authors.forename: L
authors.initials: L
authors.lastname: Shen
authors.forename: W F
authors.initials: WF
authors.lastname: Wade
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000276:immunology; D005677:G(M1) Ganglioside / Q000378:metabolism; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011940:Receptor Aggregation / Q000276:immunology*; D011961:Receptors, Fc / Q000378:metabolism / Q000502:physiology*; D017452:Receptors, IgG / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D014162:Transfection; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: C045281:IgA receptor; D007070:Immunoglobulin A; D011961:Receptors, Fc; D017452:Receptors, IgG; D005677:G(M1) Ganglioside; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases