title: An electrostatic selection mechanism controls sequential kinase signaling downstream of the T cell receptor.
abstract: The sequence of events that initiates T cell signaling is dictated by the specificities and order of activation of the tyrosine kinases that signal downstream of the T cell receptor. Using a platform that combines exhaustive point-mutagenesis of peptide substrates, bacterial surface-display, cell sorting, and deep sequencing, we have defined the specificities of the first two kinases in this pathway, Lck and ZAP-70, for the T cell receptor ζ chain and the scaffold proteins LAT and SLP-76. We find that ZAP-70 selects its substrates by utilizing an electrostatic mechanism that excludes substrates with positively-charged residues and favors LAT and SLP-76 phosphosites that are surrounded by negatively-charged residues. This mechanism prevents ZAP-70 from phosphorylating its own activation loop, thereby enforcing its strict dependence on Lck for activation. The sequence features in ZAP-70, LAT, and SLP-76 that underlie electrostatic selectivity likely contribute to the specific response of T cells to foreign antigens.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, United States.|California Institute for Quantitative Biosciences, University of California, Berkeley, United States.|Howard Hughes Medical Institute, University of California, Berkeley, United States.
authors.forename: Neel H
authors.initials: NH
authors.lastname: Shah
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, United States.|California Institute for Quantitative Biosciences, University of California, Berkeley, United States.|Howard Hughes Medical Institute, University of California, Berkeley, United States.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, United States.|California Institute for Quantitative Biosciences, University of California, Berkeley, United States.|Howard Hughes Medical Institute, University of California, Berkeley, United States.
authors.forename: Qingrong
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, United States.|California Institute for Quantitative Biosciences, University of California, Berkeley, United States.|Howard Hughes Medical Institute, University of California, Berkeley, United States.
authors.forename: Deepti
authors.initials: D
authors.lastname: Karandur
authors.affiliation: Rosalind Russell/Ephraim P Engleman Rheumatology Research Center, Department of Medicine, University of California, San Francisco, United States.|Howard Hughes Medical Institute, University of California, San Francisco, United States.
authors.forename: Theresa A
authors.initials: TA
authors.lastname: Kadlecek
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, United States.|California Institute for Quantitative Biosciences, University of California, Berkeley, United States.|Howard Hughes Medical Institute, University of California, Berkeley, United States.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Fallahee
authors.affiliation: Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: William P
authors.initials: WP
authors.lastname: Russ
authors.affiliation: Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, United States.|Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.|Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Rama
authors.initials: R
authors.lastname: Ranganathan
authors.affiliation: Rosalind Russell/Ephraim P Engleman Rheumatology Research Center, Department of Medicine, University of California, San Francisco, United States.|Howard Hughes Medical Institute, University of California, San Francisco, United States.
authors.forename: Arthur
authors.identifier: 0000-0002-2414-9024
authors.initials: A
authors.lastname: Weiss
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, United States.|California Institute for Quantitative Biosciences, University of California, Berkeley, United States.|Howard Hughes Medical Institute, University of California, Berkeley, United States.|Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States.
authors.forename: John
authors.identifier: 0000-0002-4414-5477
authors.initials: J
authors.lastname: Kuriyan
mesh_terms: D057809:HEK293 Cells; D006801:Humans; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000737:chemistry* / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D015398:Signal Transduction; D055672:Static Electricity; D013379:Substrate Specificity; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D011948:Receptors, Antigen, T-Cell; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051746:ZAP-70 Protein-Tyrosine Kinase
keywords: E. coli; LAT; Lck; T cell receptor; ZAP-70; bacterial surface display; biophysics; immunology; structural biology; tyrosine kinase