Barry, E.Felquer, F.Powell, J.Biggs, L.Stomski, F.Urbani, A.Ramshaw, H.Hoffmann, P.Wilce, M.Grimbaldeston, M.Lopez, A.Guthridge, M.2009-10-022009-10-022009Journal of Biological Chemistry, 2009; 284(18):12080-120900021-92581083-351Xhttp://hdl.handle.net/2440/51112Integrated cascades of protein tyrosine and serine/threonine phosphorylation play essential roles in transducing signals in response to growth factors and cytokines. How adaptor or scaffold proteins assemble signaling complexes through both phosphotyrosine and phosphoserine/threonine residues to regulate specific signaling pathways and biological responses is unclear. We show in multiple cell types that endogenous 14-3-3zeta is phosphorylated on Tyr(179) in response to granulocyte macrophage colony-stimulating factor. Importantly, 14-3-3zeta can function as an intermolecular bridge that couples to phosphoserine residues and also directly binds the SH2 domain of Shc via Tyr(179). The assembly of these 14-3-3:Shc scaffolds is specifically required for the recruitment of a phosphatidylinositol 3-kinase signaling complex and the regulation of CTL-EN cell survival in response to cytokine. The biological significance of these findings was further demonstrated using primary bone marrow-derived mast cells from 14-3-3zeta(-/-) mice. We show that cytokine was able to promote Akt phosphorylation and viability of primary mast cells derived from 14-3-3zeta(-/-) mice when reconstituted with wild type 14-3-3zeta, but the Akt phosphorylation and survival response was reduced in cells reconstituted with the Y179F mutant. Together, these results show that 14-3-3:Shc scaffolds can act as multivalent signaling nodes for the integration of both phosphoserine/threonine and phosphotyrosine pathways to regulate specific cellular responses.en© 2009 by The American Society for Biochemistry and Molecular Biology, Inc.Cell LineMast CellsAnimalsMice, KnockoutHumansMicePhosphotyrosinePhosphoserine14-3-3 ProteinsGranulocyte-Macrophage Colony-Stimulating FactorSignal TransductionCell SurvivalEnzyme ActivationPhosphorylationMutation, MissenseProto-Oncogene Proteins c-aktShc Signaling Adaptor ProteinsPhosphatidylinositol 3-KinasesJournal article002009055610.1074/jbc.M8076372000002654946000402-s2.0-6644909236538994Ramshaw, H. [0000-0001-9909-282X]Lopez, A. [0000-0001-7430-0135]