SLAP 130 AND THE REGULATION OF T CELL ACTIVATION

T细胞抗原受体（TCR）的结合导致蛋白质 酪氨酸激酶（PTK）激活，随后 许多蛋白质的磷酸化。以前的研究集中在 鉴定TCR诱导的PTK活性的底物导致克隆 和SLP 76的表征。SLP 76的功能是 SLP 76调节TCR介导的信号， 导致IL-2基因启动子的诱导。为了研究 为了进一步研究SLP 76在T细胞活化中的功能，我们和其他人已经 开始表征SLP-76相关蛋白。本研究 将我们的注意力集中在最近发现的SLP 76相关 130 kDa的磷蛋白，SLAP 130。序列分析显示， SLAP 130含有几个区域，这些区域可以介导其与 其他分子，尽管它缺乏任何已知的酶活性。初始 实验表明SLAP 130的过表达干扰TCR 信号传导，并且可以抑制SLP 76增强NFAT活性的能力。 尽管SLAP 130如何调节T细胞活化的机制 目前还不清楚，我们的初步研究提供了支持， SLAP 130可能作为T细胞负调节因子假说 activation.为了验证这一假设，最初的实验将涉及 SLAP 130的表达模式的表征， 造血组织和发育和T细胞成熟期间。在 此外，我们将研究哪些近端TCR介导的信号是 受SLAP 130影响。下一组实验将集中在 了解SLAP 130的结构/功能关系。我们将 确定SLAP 130中的酪氨酸磷酸化位点，并将询问 其中哪些负责SLAP 130和 SLP76。为了更好地理解SLAP 130的功能，我们建议 为了鉴定与SLAP 130相关的其他蛋白质， 这些相互作用在调节T细胞功能中是否重要。 最后，为了说明SLAP 130功能在T细胞中的重要性，我们 将使用SLAP 130“敲除”小鼠来评估T细胞功能， SLAP 130表达缺失。希望所获得的信息 从这些研究中将提供深入了解SLAP 130的功能， 调节T细胞信号传导。

Engagement of the T-cell antigen receptor (TCR) results in protein tyrosine kinase (PTK) activation followed by the subsequent phosphorylation of numerous proteins. Previous studies which focused on identifying substrates of TCR-induced PTK activity led to the cloning and characterization of SLP76. In sight into the function of SLP76 WAS provided by the findings that SLP76 regulates TCR-mediated signals that leads to induction of the IL-2 gene promoter. In order to investigate further the function of SLP76 in T-cell activation, we and others have begun to characterize SLP-76 associated proteins. In this study, we focus our attention on the recently identified SLP76 associated phosphoprotein of 130kDa, SLAP130. Sequence analysis reveals that SLAP130 contains several regions that may mediate its interaction with other molecules although it lacks any known enzymatic activity. Initial experiments show that overexpression of SLAP130 interferes with TCR signaling and can inhibit the ability of SLP76 to augment NFAT activity. Although the mechanism of how SLAP130 modulates T-cell activation remains unclear, our preliminary studies provide support for the hypothesis that SLAP130 may serve as a negative regulator of T-cell activation. To test this hypothesis, initial experiments will involve the characterization of the expression pattern of SLAP130 in hematopoietic tissues and during development and T-cell maturation. In addition, we will investigate which proximal TCR-mediated signals are affected by SLAP130. The next set of experiments will focus on understanding the structure/function relationship of SLAP130. We will identify the tyrosine phosphorylation sites in SLAP130 and will ask which of these are responsible for the interaction between SLAP130 and SLP76. In order to understand better the function of SLAP130, we propose to identify other proteins that associate with SLAP130 and will ask whether these interactions are important in modulating T-cell function. Finally, to address the importance of SLAP130 function in T-cells, we will use a SLAP130 "knock-out" mouse to assess T-cell function in the absence of SLAP130 expression. It is hoped that the information gained from these studies will provide insight into the function of SLAP130 in modulating T-cell signaling.