IFNARI SIGNALING THROUGH STAT3, PI 3 KINASE

通过 STAT3、PI 3 激酶的 IFNARI 信号传导

• 批准号: 2455285
• 负责人: LAWRENCE MARC PFEFFER
• 金额: $ 27.78万
• 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/2455285
• 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（IFN α）是一种多功能细胞因子， 临床上有效的治疗人类恶性肿瘤，病毒 感染和自身免疫性疾病。α干扰素eleiotropic多效性 通过产生信号调节基因表达的生物学效应 在其与靶细胞上的表面受体（IFN α R）结合后。的 第一个克隆的IFNalpha R亚基IFNAR 1，作为一种免疫调节剂发挥决定性作用。 IFN信号转导亚基，但不直接结合IFN α。的 干扰素α诱导的STAT转录因子酪氨酸磷酸化 在活化蛋白激酶（ERK 2）中起关键作用，也有助于IFN α 行动上根据申请人最近的研究，假设 通过IFN α诱导的STAT 3与IFN α R的结合， STAT 3（一种调节急性期反应基因的转录因子）， 将IFN α R信号传导与涉及PI-3激酶的途径偶联 （磷脂酰肌醇-3 '激酶，丝氨酸激酶中的上游元件， 转导级联），NF-κ B（核因子-κ B，转录 炎症和防止细胞凋亡中重要基因的因子），和 丝氨酸激酶（PKC亚种和ERK 2）。在具体目标1中，STAT 3 作为连接IFN α信号通路的接头， 表征了要确定的是STAT 3激活（特别是通过 STAT 3中PI-3激酶的p85亚基的对接结构域）是 IFN α诱导所需的：PI-3激酶激活，PKC激活， ERK 2激活、基因表达、抗病毒作用和抗- 增殖作用在特异性目的2中，PI-3激酶臂的作用是 将定义IFN α作用中STAT 3信号通路。效果 表达显性负性和组成型活性PI-3激酶 构建体将检查IFN α诱导的： 细胞底物，PKC活化，ERK 2活化，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， IFN α作用中STAT 3信号通路的NF-κ B组分 将被定义。有待确定的是NF-κ B的机制 活化，STAT 3与NF-κ B蛋白的相互作用， IFN-α诱导的NF-κ B活化：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 的STAT 3，PI-3激酶和NF-κ B的连接，并确定其 在影响IFN生物学作用中的作用。