title: The catalytic activity of the kinase ZAP-70 mediates basal signaling and negative feedback of the T cell receptor pathway.
abstract: T cell activation by antigens binding to the T cell receptor (TCR) must be properly regulated to ensure normal T cell development and effective immune responses to pathogens and transformed cells while avoiding autoimmunity. The Src family kinase Lck and the Syk family kinase ZAP-70 (ζ chain-associated protein kinase of 70 kD) are sequentially activated in response to TCR engagement and serve as critical components of the TCR signaling machinery that leads to T cell activation. We performed a mass spectrometry-based phosphoproteomic study comparing the quantitative differences in the temporal dynamics of phosphorylation in stimulated and unstimulated T cells with or without inhibition of ZAP-70 catalytic activity. The data indicated that the kinase activity of ZAP-70 stimulates negative feedback pathways that target Lck and thereby modulate the phosphorylation patterns of the immunoreceptor tyrosine-based activation motifs (ITAMs) of the CD3 and ζ chain components of the TCR and of signaling molecules downstream of Lck, including ZAP-70. We developed a computational model that provides a mechanistic explanation for the experimental findings on ITAM phosphorylation in wild-type cells, ZAP-70-deficient cells, and cells with inhibited ZAP-70 catalytic activity. This model incorporated negative feedback regulation of Lck activity by the kinase activity of ZAP-70 and predicted the order in which tyrosines in the ITAMs of TCR ζ chains must be phosphorylated to be consistent with the experimental data.
authors.affiliation: Howard Hughes Medical Institute, UCSF, San Francisco, CA 94143, USA.|Department of Medicine, UCSF, San Francisco, CA 94143, USA.
authors.forename: Hanna Sjölin
authors.initials: HS
authors.lastname: Goodfellow
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Frushicheva
authors.affiliation: Department of Chemistry, Brown University, Providence, RI 02912, USA.
authors.forename: Qinqin
authors.initials: Q
authors.lastname: Ji
authors.affiliation: Howard Hughes Medical Institute, UCSF, San Francisco, CA 94143, USA.|Department of Medicine, UCSF, San Francisco, CA 94143, USA.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Cheng
authors.affiliation: Howard Hughes Medical Institute, UCSF, San Francisco, CA 94143, USA.|Department of Medicine, UCSF, San Francisco, CA 94143, USA.
authors.forename: Theresa A
authors.initials: TA
authors.lastname: Kadlecek
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.|California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Cantor
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.|California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA.|Department of Chemistry, University of California, Berkeley, CA 94720, USA.|Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA.|Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kuriyan
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.|Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.|Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.|Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.|Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.|Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA.
authors.forename: Arup K
authors.initials: AK
authors.lastname: Chakraborty
authors.affiliation: Department of Chemistry, Brown University, Providence, RI 02912, USA.|Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Salomon
authors.affiliation: Howard Hughes Medical Institute, UCSF, San Francisco, CA 94143, USA.|Department of Medicine, UCSF, San Francisco, CA 94143, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Weiss
mesh_terms: D002384:Catalysis; D025461:Feedback, Physiological / Q000502:physiology*; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D019169:Jurkat Cells; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000378:metabolism*; D013058:Mass Spectrometry; D018448:Models, Immunological; D010748:Phosphopeptides / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D040901:Proteomics / Q000379:methods; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology*; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000378:metabolism*
chemical_list: D010748:Phosphopeptides; D011948:Receptors, Antigen, T-Cell; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051746:ZAP-70 Protein-Tyrosine Kinase