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）：必须严格调节由炎症刺激触发的免疫反应。不受限制的炎症与免疫疾病有关。细胞外炎症性刺激向细胞核信号限制炎症基因激活的理解很少。 NF？b和Stats是两个重要的转录因子系列，这些家族被多种促炎性刺激激活以诱导基因表达。活化STAT1（PIAS1）的蛋白质抑制剂通过选择性地阻断NF？B和STAT1与基因启动子的结合来抑制免疫反应。我们最近确定了一种新的信号通路，其中促炎性刺激激活了IKKA介导的PIAS1磷酸化，以立即抑制炎症基因激活。该研究建议的总体目标是在免疫反应调节中表征IKKA-PIAS1信号通路。具体而言，我们将通过突变分析和激酶测定法表征IKKA介导的PIAS1 Ser90磷酸化的分子基础。 IKK家族其他成员的作用以及IKK在介导PIAS1 Ser90磷酸化中的特异性将使用IKK基因敲除细胞进行检查。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启动子募集中的作用。我们将分析PIAS1 SAP结构域在PIAS1的Ser90磷酸化依赖性启动子募集中的作用。我们将测试Ser90磷酸化是否足以使用Ser90磷酸突变体将PIAS1靶向基因启动子。 PIAS1的启动子结合区域将通过CHIP分析和突变分析来检查。最后，我们将生成PIAS1磷酸化缺陷型小鼠模型，以研究PIAS1磷酸化对致病感染的生理功能。这些研究将研究一种新型的分子信号传导机制，用于负调控免疫反应，这将增强我们设计有理治疗策略来治疗传染病和炎症性疾病的能力。与公共卫生的相关性：必须严格调节炎症刺激引起的免疫反应。无限制的炎症与免疫疾病和癌症有关。该建议是研究一种新近识别的信号通路，该信号通路能够平衡免疫反应。这些研究将增强我们设计用于治疗免疫疾病的新型治疗策略的能力。