T cell receptor activation of a ribosomal S6 kinase activity.
Stimulation of the T cell receptor-CD3 complex activates multiple signal transduction pathways, including serine/threonine and tyrosine protein kinases. Stimulation of the human T cell line Jurkat via the T cell receptor-CD3 complex with anti-CD3 monoclonal antibody or incubation with the tumor promoter phorbol 12-myristate 13-acetate caused increases in S6 kinase and microtubule-associated protein 2 (MAP) kinase activities. An S6 kinase activity that was able to phosphorylate exogenous 40S ribosomal S6 protein was recovered in immunoprecipitates obtained using a 90-kDa ribosomal S6 kinase-specific antiserum and thus represents activation of a member of the 90-kDa ribosomal S6 kinase family. Stimulation of the S6 kinase activity correlated with an increase in a kinase activity able to phosphorylate exogenous 90-kDa ribosomal S6 kinase (rsk) attributed to a MAP kinase activity. These increases in S6 and MAP kinase activities further correlated with the appearance of a 42-kDa phosphoprotein detected by anti-phosphotyrosine immunoblotting. However, while the tyrosine phosphorylation of the 42-kDa protein and the MAP kinase activity are dependent on protein kinase C activity, residual S6 kinase activity can be detected following protein kinase C depletion and subsequent anti-CD3 stimulation. Thus, T cell activation through the T cell receptor-CD3 complex results in activation of a member of the 90-kDa S6 kinase family which correlates with, but can be independent of, MAP kinase activation.
Calvo
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Division of Pediatric Oncology, Dana-Farber Cancer Institute, MA 02115.
Bierer
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BE
Vik
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TA
D004789:Enzyme Activation; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D038601:Ribosomal Protein S6; D019893:Ribosomal Protein S6 Kinases; D012269:Ribosomal Proteins / Q000378:metabolism*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins; D011494:Protein Kinases; D019893:Ribosomal Protein S6 Kinases; D011493:Protein Kinase C