IFNARI SIGNALING THROUGH STAT3, PI 3 KINASE

通过 STAT3、PI 3 激酶的 IFNARI 信号传导

• 批准号: 6475950
• 负责人: LAWRENCE MARC PFEFFER
• 金额: $ 30.15万
• 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/6475950
• 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是一种多功能的细胞因子，它是 临床上有效地治疗人类恶性肿瘤、病毒性疾病 感染和自身免疫性疾病。干扰素α诱导多效性 通过产生的信号调节基因表达的生物效应 当它与靶细胞表面受体(IFNalphaR)结合时。这个 第一个克隆的IFNalphaR亚基，IFNAR1，起着决定性的作用 干扰素信号转导亚单位，但不直接结合干扰素α。这个 干扰素α诱导STAT转录因子酪氨酸磷酸化 关键的活化蛋白激酶(ERK2)也对IFNpha起作用 行动。根据申请人最近的研究，假设是 测试的是通过IFNpha诱导的STAT3与IFNalphaR的结合， STAT3(一种调节急性时相反应基因的转录因子)， 将IFNalphaR信号偶联到PI-3激酶途径 (磷脂酰肌醇-3‘激酶，丝氨酸激酶的上游元件 转导级联)，核因子-kappaB(核因子-kappaB，转录因子 炎症和防止细胞凋亡的重要基因的因子)，以及 丝氨酸激酶(PKC亚种和ERK2)。在具体目标1中，STAT3如何 充当连接IFNpha信号通路的适配器 特色化的。需要确定的是STAT3是否被激活(特别是通过 PI-3激酶P85亚单位在STAT3中的对接结构域)是 在干扰素α诱导下所必需的：PI-3激酶激活，PKC激活， ERK2的激活、基因表达、抗病毒作用和抗病毒作用 增殖作用。在特异靶2中，PI-3激酶臂的作用 将定义在IFNpha作用中的STAT3信号通路。其效果 表达显性负性和结构性活性PI-3的研究 构建物将被检测由IFNpha诱导的丝氨酸磷酸化。 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， 和抑制细胞程序性死亡。在具体目标3中， 转录因子α作用中STAT3信号通路中的核因子-kappaB组分 将会被定义。有待确定的是核因子-kappaB的机制 STAT3与核因子-kappaB蛋白的激活、相互作用及其作用 核因子-kappaB在干扰素α诱导下的激活：基因表达，抗病毒 程序化细胞的活性、抗增殖活性、抑制作用 死亡。这些研究的总体目标是确定激活是如何 STAT3、PI-3激酶和NF-kappaB是连锁的，并确定它们的 在影响干扰素生物学作用中的作用。