Docking Protein Gab2 Is Phosphorylated by ZAP-70 and Negatively Regulates T Cell Receptor Signaling by Recruitment of Inhibitory Molecules

Shou Yamasaki, Keigo Nishida, Masahiko Hibi, Machie Sakuma, Ritsuko Shiina, Arata Takeuchi, Hiroshi Ohnishi, Toshio Hirano, Takashi Saito

    Research output: Contribution to journalArticle

    65 Citations (Scopus)

    Abstract

    To maintain various T cell responses and immune equilibrium, activation signals triggered by T cell antigen receptor (TCR) must be regulated by inhibitory signals. Gab2, an adaptor protein of the insulin receptor substrate-1 family, has been shown to be involved in the downstream signaling from cytokine receptors. We investigated the functional role of Gab2 in TCR-mediated signal transduction. Gab2 was phosphorylated by ZAP-70 and co-precipitated with phosphoproteins, such as ZAP-70, LAT, and CD3ζ, upon TCR stimulation. Overexpression of Gab2 in Jurkat cells or antigen-specific T cell hybridomas resulted in the inhibition of NF-AT activation, interleukin-2 production, and tyrosine phosphorylation. The structure-function relationship of Gab2 was analyzed by mutants of Gab2. The Gab2 mutants lacking SHP-2-binding sites mostly abrogated the inhibitory activity of Gab2, but its inhibitory function was restored by fusing to active SHP-2 as a chimeric protein. A mutant with defective phosphatidylinositol 3-kinase binding capacity also impaired the inhibitory activity, and the pleckstrin homology domain-deletion mutant revealed a crucial function of the pleckstrin homology domain for localization to the plasma membrane. These results suggest that Gab2 is a substrate of ZAP-70 and functions as a switch molecule toward inhibition of TCR signal transduction by mediating the recruitment of inhibitory molecules to the TCR signaling complex.

    Original languageEnglish
    Pages (from-to)45175-45183
    Number of pages9
    JournalJournal of Biological Chemistry
    Volume276
    Issue number48
    DOIs
    Publication statusPublished - Nov 30 2001

    Fingerprint

    T-Cell Antigen Receptor
    Molecules
    Signal transduction
    T-cells
    Proteins
    Signal Transduction
    Chemical activation
    Phosphatidylinositol 3-Kinase
    T-Lymphocytes
    Insulin Receptor Substrate Proteins
    Phosphorylation
    Cytokine Receptors
    Jurkat Cells
    Phosphoproteins
    Hybridomas
    Cell membranes
    Interleukin-2
    Tyrosine
    Binding Sites
    Switches

    All Science Journal Classification (ASJC) codes

    • Biochemistry

    Cite this

    Docking Protein Gab2 Is Phosphorylated by ZAP-70 and Negatively Regulates T Cell Receptor Signaling by Recruitment of Inhibitory Molecules. / Yamasaki, Shou; Nishida, Keigo; Hibi, Masahiko; Sakuma, Machie; Shiina, Ritsuko; Takeuchi, Arata; Ohnishi, Hiroshi; Hirano, Toshio; Saito, Takashi.

    In: Journal of Biological Chemistry, Vol. 276, No. 48, 30.11.2001, p. 45175-45183.

    Research output: Contribution to journalArticle

    Yamasaki, S, Nishida, K, Hibi, M, Sakuma, M, Shiina, R, Takeuchi, A, Ohnishi, H, Hirano, T & Saito, T 2001, 'Docking Protein Gab2 Is Phosphorylated by ZAP-70 and Negatively Regulates T Cell Receptor Signaling by Recruitment of Inhibitory Molecules', Journal of Biological Chemistry, vol. 276, no. 48, pp. 45175-45183. https://doi.org/10.1074/jbc.M105384200
    Yamasaki, Shou ; Nishida, Keigo ; Hibi, Masahiko ; Sakuma, Machie ; Shiina, Ritsuko ; Takeuchi, Arata ; Ohnishi, Hiroshi ; Hirano, Toshio ; Saito, Takashi. / Docking Protein Gab2 Is Phosphorylated by ZAP-70 and Negatively Regulates T Cell Receptor Signaling by Recruitment of Inhibitory Molecules. In: Journal of Biological Chemistry. 2001 ; Vol. 276, No. 48. pp. 45175-45183.
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    AU - Sakuma, Machie

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