Signaling to PIAS1 to Regulate Immune Responses

向 PIAS1 发出信号以调节免疫反应

• 批准号: 7666870
• 负责人: KE SHUAI
• 金额: $ 29.26万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7666870
• 关键词: Binding; Biological Assay; Cell Nucleus; Cells; Disease; Equilibrium; Family; Gene Activation; Gene Expression; Genes; Genetic Transcription; Goals; Immune; Immune System Diseases; Immune response; Immune system; Infection; Inflammation; Inflammatory; Knock-out; Ligands; Ligase; Malignant Neoplasms; Mediating; Molecular; Phosphorylation; Phosphotransferases; Physiological; Protein Kinase; Protein Region; Proteins; Public Health; Regulation; Repression; Research Proposals; Role; STAT1 gene; STAT1 protein; Signal Pathway; Signal Transduction; Specificity; Stimulus; TNF gene; Testing; Therapeutic; Ubiquitin; activating transcription factor; base; design; extracellular; inhibitor/antagonist; member; mouse model; mutant; novel; novel therapeutics; promoter; protein function; response; treatment strategy; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The immune responses triggered by inflammatory stimuli must be tightly regulated. Unrestricted inflammation is associated with immune disorders. How extracellular inflammatory stimuli signal to the nucleus to restrict inflammatory gene activation is poorly understood. NF?B and STATs are two important families of transcription factors that are activated by a wide variety of pro-inflammatory stimuli to induce gene expression. Protein inhibitor of activated STAT1 (PIAS1) inhibits immune responses by selectively blocking the binding of NF?B and STAT1 to gene promoters. We have recently identified a novel signaling pathway in which pro- inflammatory stimuli activate the IKKa-mediated phosphorylation of PIAS1 for the immediate repression of inflammatory gene activation. The overall goal of this research proposal is to characterize the IKKa-PIAS1 signaling pathway in the regulation of immune responses. Specifically, we will characterize the molecular basis of the IKKa-mediated PIAS1 Ser90 phosphorylation by mutational analysis and kinase assays. The role of other members of the IKK family and the specificity of IKKs in mediating PIAS1 Ser90 phosphorylation will be examined using IKK knockout cells. Next, we will investigate how PIAS1 phosphorylation regulates the activity of PIAS1. We will examine the role of PIAS1 Ser90 phosphorylation in the ligand-induced promoter recruitment of PIAS1. We will analyze the role of PIAS1 SAP domain in the Ser90 phosphorylation-dependent promoter recruitment of PIAS1. We will test if Ser90 phosphorylation is sufficient to target PIAS1 to gene promoters using Ser90 phosphomimic mutants. The promoter binding region(s) of PIAS1 will be examined by ChIP assays and mutational analysis. Finally, we will generate a PIAS1 phosphorylation-defective knockin mouse model to study the physiological function of PIAS1 phosphorylation in response to pathogenic infection. These studies will investigate a novel molecular signaling mechanism for the negative regulation of immune responses, which will enhance our ability to design rational therapeutic strategies for the treatment of infectious and inflammatory diseases. RELEVANCE TO PUBLIC HEALTH: The immune responses triggered by inflammatory stimuli must be tightly regulated. Unrestricted inflammation is associated with immune disorders and cancer. This proposal is to study a newly identified signaling pathway that functions to balance immune responses. These studies will enhance our ability to design novel therapeutic strategies for the treatment of immune diseases.

描述（由申请人提供）：由炎症刺激引发的免疫反应必须受到严格调节。不受限制的炎症与免疫紊乱有关。人们对细胞外炎症刺激如何向细胞核发出信号以限制炎症基因激活知之甚少。 NFκB 和 STAT 是两个重要的转录因子家族，它们被多种促炎刺激激活以诱导基因表达。活化 STAT1 的蛋白抑制剂 (PIAS1) 通过选择性阻断 NFκB 和 STAT1 与基因启动子的结合来抑制免疫反应。我们最近发现了一种新的信号通路，其中促炎刺激激活 IKKa 介导的 PIAS1 磷酸化，从而立即抑制炎症基因激活。本研究计划的总体目标是表征免疫反应调节中的 IKKa-PIAS1 信号通路。具体来说，我们将通过突变分析和激酶测定来表征 IKKa 介导的 PIAS1 Ser90 磷酸化的分子基础。将使用 IKK 敲除细胞检查 IKK 家族其他成员的作用以及 IKK 在介导 PIAS1 Ser90 磷酸化中的特异性。接下来，我们将研究PIAS1磷酸化如何调节PIAS1的活性。我们将研究 PIAS1 Ser90 磷酸化在配体诱导的 PIAS1 启动子招募中的作用。我们将分析 PIAS1 SAP 结构域在 PIAS1 Ser90 磷酸化依赖性启动子招募中的作用。我们将使用 Ser90 磷酸化突变体测试 Ser90 磷酸化是否足以将 PIAS1 靶向基因启动子。 PIAS1 的启动子结合区将通过 ChIP 测定和突变分析进行检查。最后，我们将构建PIAS1磷酸化缺陷型敲入小鼠模型，以研究PIAS1磷酸化响应病原体感染的生理功能。这些研究将研究免疫反应负调节的新型分子信号传导机制，这将增强我们设计合理治疗策略来治疗传染性和炎症性疾病的能力。与公众健康的相关性：由炎症刺激引发的免疫反应必须受到严格监管。不受限制的炎症与免疫紊乱和癌症有关。该提案旨在研究一种新发现的具有平衡免疫反应功能的信号通路。这些研究将增强我们设计治疗免疫疾病的新治疗策略的能力。