title: Impaired tyrosine phosphorylation and Ca2+ mobilization, but not degranulation, in lyn-deficient bone marrow-derived mast cells.
abstract: Signaling through the high affinity IgE receptor (Fc epsilon RI) on mast cells and basophils results in rapid increases in tyrosine phosphorylation on a number of proteins. Fc epsilon RI associates with two classes of the tyrosine kinases, the Src family kinases, such as Lyn, c-Yes, and c-Src, and the Syk kinase. In this work, using primary mast cells derived from wild-type (lyn +/+) and lyn-deficient (lyn -/-) mice, we report that Lyn plays a part in signaling via Fc epsilon RI. Unlike lyn +/+ mast cells, cross-linking of Fc epsilon RI in lyn -/- mast cells failed to induce protein-tyrosine phosphorylation of various substrates, and evoked a delayed and slow Ca2+ mobilization. However, degranulation, adhesion, and production of cytokines occurred normally in lyn -/- mast cells. Our data suggest that the activity of the other Src family kinases, such as c-Src, can complement the role of Lyn in inducing most, but not all, biologic and biochemical responses to Fc epsilon RI cross-linking.
authors.affiliation: Department of Oncology, Institute of Medical Science, University of Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nishizumi
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000473:pathology*; D002118:Calcium / Q000378:metabolism*; D002448:Cell Adhesion / Q000276:immunology; D015550:Cell Degranulation / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002455:Cell Division; D016207:Cytokines / Q000096:biosynthesis; D008407:Mast Cells / Q000201:enzymology* / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008817:Mice, Mutant Strains; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism*; D017455:Receptors, IgE / Q000502:physiology; D019061:src-Family Kinases / Q000172:deficiency* / Q000378:metabolism*
chemical_list: D016207:Cytokines; D017455:Receptors, IgE; D019000:Phosphotyrosine; D019061:src-Family Kinases; D002118:Calcium