title: Temporal regulation of non-transmembrane protein tyrosine kinase enzyme activity following T cell antigen receptor engagement.
abstract: We evaluated in Jurkat T cells the time-dependent responses of Fyn, Lck, Syk, and Zap following antibody-mediated cross-linking of the T cell antigen receptor. Our results show that the protein kinase activities of Fyn and Lck were activated within seconds of receptor cross-linking. Fyn activity, as measured by autophosphorylation and tyrosine phosphorylation of an exogenous substrate, was maximal 5 s to 1 min following receptor cross-linking. Lck was also found to be activated within 5 s of antigen receptor cross-linking but differed from Fyn in that Lck activity was elevated for at least 30 min. Syk and Zap protein kinase activities were found to peak between 5 and 10 min following receptor cross-linking, returning to approximately basal activity levels by 60 min. The protein kinase activities of both Syk and Zap were found to parallel their reactivity in immunoblotting experiments with anti-phosphotyrosine antibodies. Both Syk and Zap were found to associate with the tyrosine-phosphorylated zeta subunit of the T cell antigen receptor. These observations imply that T cell antigen receptor signal transduction involves the activation of multiple members of at least two different families of non-transmembrane protein tyrosine kinases.
authors.affiliation: Department of Molecular Biology, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543.
authors.forename: A L
authors.initials: AL
authors.lastname: Burkhardt
authors.forename: B
authors.initials: B
authors.lastname: Stealey
authors.forename: R B
authors.initials: RB
authors.lastname: Rowley
authors.forename: S
authors.initials: S
authors.lastname: Mahajan
authors.forename: M
authors.initials: M
authors.lastname: Prendergast
authors.forename: J
authors.initials: J
authors.lastname: Fargnoli
authors.forename: J B
authors.initials: JB
authors.lastname: Bolen
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D008969:Molecular Sequence Data; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D015398:Signal Transduction; D000072377:Syk Kinase; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D051746:ZAP-70 Protein-Tyrosine Kinase
chemical_list: D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D011518:Proto-Oncogene Proteins; D011948:Receptors, Antigen, T-Cell; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C494957:FYN protein, human; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn; C000606896:SYK protein, human; D000072377:Syk Kinase; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human