IFNARI SIGNALING THROUGH STAT3, PI 3 KINASE

通过 STAT3、PI 3 激酶的 IFNARI 信号传导

• 批准号: 6124542
• 负责人: LAWRENCE MARC PFEFFER
• 金额: $ 29.03万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-12-02 至 2002-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6124542
• 关键词: DNA binding protein; SDS polyacrylamide gel electrophoresis; antiviral agents; apoptosis; biological response modifiers; biological signal transduction; cell growth regulation; densitometry; gene expression; immunoprecipitation; interferon alpha; northern blottings; nuclear factor kappa beta; nuclear runoff assay; phosphatidylinositol 3 kinase; phosphorylation; protein kinase C; protein structure function; receptor binding; receptor coupling; tissue /cell culture; transcription factor; western blottings

Interferon-alpha (IFNalpha) is a multifunctional cytokine, which is clinically effective in the treatment of human malignancies, viral infections and auto-immune diseases. IFNalpha elicits pleiotropic biological effects by regulating gene expression through signals generated upon its binding to a surface receptor on target cells (IFNalphaR). The first cloned subunit of the IFNalphaR, IFNAR1, plays a decisive role as a IFN signal transducing subunit but does not directly bind IFNalpha. The IFNalpha-induced tyrosine phosphorylation of STAT transcription factors is crucial in activated protein kinase (ERK2) also contribute to IFNalpha action. Based on the applicant's recent studies, the hypothesis to be tested is that via the IFNalpha-induced binding of STAT3 to the IFNalphaR, STAT3 (a transcription factor regulation the acute phase response genes), couples IFNalphaR signaling to pathways involving PI-3 kinase (phosphatidylinositol-3' kinase, an upstream element in a serine kinase transduction cascade), NF-kappaB (nuclear factor-kappaB, a transcription factor for genes important in inflammation and preventing apoptosis), and serine kinases (PKC subspecies and ERK2). In Specific Aim 1, how STAT3 acts as an adapter to couple IFNalpha signaling pathways will be characterized. To be determined is if STAT3 activation (specifically via the docking domain in STAT3 for the p85 subunit of PI-3 kinase) is required for IFNalpha-induced: PI-3 kinase activation, PKC activation, ERK2 activation, gene expression, anti-viral action, and the anti- proliferative action. In Specific Aim 2, the role of PI-3 kinase arm of the STAT3-signaling pathway in IFNalpha action will be defined. The effect of expressing dominant negative and constitutively active PI-3 kinase constructs will be examined on IFNalpha-induced: serine phosphorylation of cellular substrates, PKC activation, ERK2 activation, DNA-binding activity, gene expression, anti-viral action, anti-proliferative action, and inhibition of programmed cell death. In specific Aim 3, the role of the NF-kappaB component of the STAT3-signaling pathway in IFNalpha action will be defined. To be determine are the mechanism for NF-kappaB activation, the interaction of STAT3 with NF-kappaB proteins, and the role of NF-kappaB activation on IFNalpha-induced: gene expression, anti-viral activity, anti-proliferative activity, inhibition of programmed cell death. The overall goal of these studies to determine how the activation of STAT3, PI-3 kinase and NF-kappaB are linked, and to determine their roles in effecting IFN's biological actions.

干扰素-α（IFNα）是一种多功能细胞因子， 临床上可有效治疗人类恶性肿瘤、病毒性疾病 感染和自身免疫性疾病。 IFNα 引发多效性 通过产生的信号调节基因表达来产生生物学效应 其与靶细胞表面受体 (IFNαR) 结合。这 IFNαR 的第一个克隆亚基 IFNAR1 作为 IFN信号转导亚基但不直接结合IFNα。这 IFNα诱导的STAT转录因子酪氨酸磷酸化是 对激活蛋白激酶 (ERK2) 至关重要，也有助于 IFNα 行动。根据申请人最近的研究，假设是 测试的是通过 IFNα 诱导的 STAT3 与 IFNαR 的结合， STAT3（调节急性期反应基因的转录因子）， 将 IFNαR 信号传导与涉及 PI-3 激酶的通路结合起来 （磷脂酰肌醇-3' 激酶，丝氨酸激酶的上游元件 转导级联）、NF-kappaB（核因子-kappaB，一种转录因子） 炎症和预防细胞凋亡中重要基因的因子），以及 丝氨酸激酶（PKC 亚种和 ERK2）。在具体目标 1 中，STAT3 如何 作为连接 IFNα 信号通路的适配器 特点。待确定的是 STAT3 是否激活（具体通过 STAT3 中 PI-3 激酶 p85 亚基的对接域）是 IFNα 诱导所需：PI-3 激酶激活、PKC 激活、 ERK2 激活、基因表达、抗病毒作用和抗 增殖作用。在具体目标 2 中，PI-3 激酶臂的作用 IFNα 作用中的 STAT3 信号通路将被定义。效果 表达显性失活和组成型活性 PI-3 激酶 将检查 IFNα 诱导的构建体：丝氨酸磷酸化 细胞底物、PKC 激活、ERK2 激活、DNA 结合 活性、基因表达、抗病毒作用、抗增殖作用、 和抑制程序性细胞死亡。在具体目标 3 中， STAT3 信号通路的 NF-kappaB 成分在 IFNα 作用中的作用 将被定义。 NF-kappaB 的作用机制尚待确定 STAT3 与 NF-kappaB 蛋白的激活、相互作用以及作用 NF-κB 激活对 IFNα 诱导的影响：基因表达、抗病毒 活性，抗增殖活性，抑制程序化细胞 死亡。这些研究的总体目标是确定如何激活 STAT3、PI-3激酶和NF-kappaB是相连的，并确定它们的 干扰素在影响干扰素生物学作用中的作用。