Milia E, Di Somma M M, Baldoni F, Chiari R, Lanfrancone L, Pelicci P G, Telford J L, Baldari C T
IRIS, Siena, Italy.
Oncogene. 1996 Aug 15;13(4):767-75.
T-cell antigen receptor stimulation results in recruitment to the zeta chain and phosphorylation both of the syk family protein tyrosine kinase ZAP-70 and of the Shc adaptor protein, which transduces activating signals to Ras. Both ZAP-70 and Ras are required for T-cell activation. We have investigated the functional link between these two molecules in TCR signaling. She was found to associate with ZAP-70 in response to TCR triggering. This association was dependent on the presence of the aminoterminal phosphotyrosine binding (PTB) domain of She. The analysis of She binding to a potential PTB domain binding site on ZAP-70 confirmed the interaction of the She PTB domain with ZAP-70 and identified the ZAP-70 phosphotyrosine residue involved in this interaction. To test the role of the She PTB domain in transducing TCR derived signals we measured the effects of the isolated She PTB domain on the activation of the T-cell specific transcription factor NF-AT. The isolated She PTB domain was designed to compete non productively with endogenous She for binding to up-stream tyrosine phosphorylated proteins and thus interfere with coupling to regulators of Ras activation. A significant inhibition of NF-AT activation by TCR triggering was observed, showing a functional involvement of She in TCR signaling through its PTB domain and suggesting an important role for She association with ZAP-70.
T细胞抗原受体刺激导致syk家族蛋白酪氨酸激酶ZAP - 70和Shc衔接蛋白募集到ζ链并发生磷酸化，Shc衔接蛋白将激活信号转导至Ras。ZAP - 70和Ras都是T细胞激活所必需的。我们研究了TCR信号传导中这两个分子之间的功能联系。发现Shc在TCR触发时与ZAP - 70结合。这种结合依赖于Shc氨基末端磷酸酪氨酸结合（PTB）结构域的存在。对Shc与ZAP - 70上潜在的PTB结构域结合位点的结合分析证实了Shc PTB结构域与ZAP - 70的相互作用，并确定了参与这种相互作用的ZAP - 70磷酸酪氨酸残基。为了测试Shc PTB结构域在转导TCR衍生信号中的作用，我们测量了分离的Shc PTB结构域对T细胞特异性转录因子NF - AT激活的影响。分离的Shc PTB结构域被设计用于与内源性Shc非竞争性地结合上游酪氨酸磷酸化蛋白，从而干扰与Ras激活调节剂的偶联。观察到TCR触发对NF - AT激活有显著抑制作用，表明Shc通过其PTB结构域在TCR信号传导中发挥功能作用，并暗示Shc与ZAP - 70结合具有重要作用。
