Regulation of Vav-SLP-76 binding by ZAP-70 and its relevance to TCR zeta/CD3 induction of interleukin-2.
T cell activation stimulates p56(lck), p59(fyn), ZAP-70, Vav-SLP-76 binding, and IL-2 transcription. Major questions concern the tyrosine-kinase and relevant site(s) needed for Vav-SLP-76 complex formation and its role in IL-2 production. Here, we show that of the three kinases, only ZAP-70 phosphorylates SLP-76 at specific sites that allow Vav SH2 domain binding. Therefore, while p56(lck) regulates proximal events, ZAP-70 acts downstream on targets such as SLP-76. We also show by in vitro and in vivo analysis that two SLP-76 pYESP motifs (Y113 and Y128) mediate binding, the first being more efficient. A third pYEPP motif (Y145) failed to bind. Finally, TCR zeta CD3 ligation of T cell hybridoma DC27.10 induces IL-2 production without detectable Vav-SLP-76 binding. Therefore, despite effects of Vav-SLP-76 on IL-2 expression, Vav-SLP-76 binding per se is not essential for IL-2 production in all T cells.
Raab
M
M
Division of Tumor Immunology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
da Silva
A J
AJ
Findell
P R
PR
Rudd
C E
CE
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000378:metabolism*; D019169:Jurkat Cells; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D015513:Oncogene Proteins / Q000187:drug effects* / Q000378:metabolism*; D010750:Phosphoproteins / Q000187:drug effects* / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000494:pharmacology*; D051567:Proto-Oncogene Proteins c-vav; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D051746:ZAP-70 Protein-Tyrosine Kinase
D048868:Adaptor Proteins, Signal Transducing; D007376:Interleukin-2; D008565:Membrane Proteins; D015513:Oncogene Proteins; D010750:Phosphoproteins; D051567:Proto-Oncogene Proteins c-vav; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D011948:Receptors, Antigen, T-Cell; C092947:SLP-76 signal Transducing adaptor proteins; C496618:VAV1 protein, human; C496619:Vav1 protein, mouse; C054979:antigen T cell receptor, zeta chain; D011505:Protein-Tyrosine Kinases; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; C497262:Zap70 protein, mouse