Regulation of Vav–SLP-76 Binding by ZAP-70 and Its Relevance to TCRζ/CD3 Induction of Interleukin-2

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• 作者：Monika Raab ; Antonio J.da Silva ; Paul R. Findell ; Christopher E. Rudd
• 刊名：Immunity
• 出版年：1997
• 出版时间：February 1997
• 年：1997
• 卷：6
• 期：2
• 页码：155-164
• 全文大小：2498 K

文摘

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, TCRζ/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.