4PS MEDIATED SIGNALING PATHWAY IN IL4 SYSTEM

该修订的提案（IR 29 AI 38456 - 01）关注分子生物学。 IL-4信号传导中4PS介导的途径的剖析。4PS是180 kDa 在IL-4刺激过程中酪氨酸磷酸化的蛋白质。 最近，4PS蛋白被纯化并分离了其cDNA。初步 数据直接表明，4PS在IL-4中起着重要作用 发信号。全面了解4PS介导的IL-2信号通路 IL-4系统在科学和临床上都很重要，因为IL-4在细胞内起着重要的作用。 在保护性免疫反应的调节中起关键作用， 限制自身免疫引起的组织损伤， 某些肿瘤细胞。IL-4还控制B细胞中的IG类转换 从IgM到IgGl（人中的IgG 4）和到IgE，其通常与免疫球蛋白结合。 过敏性疾病，如哮喘和花粉热。了解 IL-4信号传导的分子机制可能为 控制和干预这些病理生理过程。 IL-4信号系统参与酪氨酸激酶的激活， 4PS的磷酸化和转录因子的激活; 然而，响应于IL-4而磷酸化4PS的激酶没有 与核事件有关的信号尚未得到确认， 确立了习该提案使用最近克隆的4PS分子， 研究IL-4受体复合物4PS 激酶、4PS磷酸化和转录因子激活 IL-4信号转导。以下具体目标将界定和探讨 在接下来的五年里，IL-4信号系统中的元素， 由4PS控制 1. IL-4受体复合物与4PS相互作用的机制 将通过合理设计的4PS突变分析进行研究 和IL-4受体的α亚单位。 2.磷酸化4PS的酪氨酸激酶（4PS激酶） 将通过细胞质和膜的分级分离来鉴定IL-4 蛋白质，并进行了表征。激酶在IL-4中的重要性 将研究信令。 3. 4PS的磷酸化与4PS的激活之间的联系 转录因子在流感信号通路中的作用将得以确立。 在表达IL-4 α亚单位的32 D细胞中过表达4PS 受体将允许识别潜在的4PS介导的 可能参与IL-4诱导的细胞凋亡的转录因子（4PS-TF） 增殖或分化。

This revised proposal (l R29 AI38456-Ol) focuses on the molecular dissection of 4PS-mediated pathways in lL-4 signaling. 4PS is a 180 kDa protein that becomes tyrosine phosphorylated during IL-4 stimulation. Recently, 4PS protein was purified and its cDNA was isolated. Preliminary data directly demonstrated that 4PS plays an important role in lL-4 signaling. A full understanding of 4PS-mediated signaling pathways in IL- 4 system is scientifically and clinically important because IL-4 plays a crucial role in the regulation of protective immune responses, in limiting tissue damage by autoimmunity, and in immune elimination of certain tumor cells. IL-4 also controls the Ig class switching in B cells from IgM to IgGl (IgG4 in human) and to IgE, which is commonly associated with allergic diseases such as asthma and hay fever. Understanding the molecular mechanisms of IL-4 signaling may provide opportunities for controlling and intervening in these pathophysiological processes. IL-4 signaling system is involved in the activation of tyrosine kinases, phosphorylation of 4PS, and the activation of transcription factors; however, the kinase that phosphorylates 4PS in response to IL-4 has not been identified, and the signals linking to nuclear events have not been established. This proposal uses the recently cloned 4PS molecule to investigate the molecular linkage between the IL-4 receptor complex, 4PS kinase, phosphorylation of 4PS and activation of transcription factors in IL-4 signaling. The following specific aims will define and explore over the next five years elements in the IL-4 signaling system that are controlled by 4PS. 1. The mechanism of interaction between the IL-4 receptor complex and 4PS will be investigated by a rationally designed mutational analysis of 4PS and the alpha subunit of the IL-4 receptor. 2. The tyrosine kinases that phosphorylate 4PS (4PS kinase) in response to IL-4 will be identified by fractionation of cytoplasmic and membrane proteins, and characterized. The importance of the kinase in IL-4 signaling will be investigated. 3. The connection between phosphorylation of 4PS and the activation of transcription factors in flu signaling pathway will be established. Overexpressing 4PS in 32D cells expressing the alpha subunit of the IL-4 receptors will allow the identification of potential 4PS-mediated transcription factors (4PS-TF) that may be involved in IL-4-induced cell proliferation or differentiation.