Understanding the importance of IkB-b as a selective co-activator of NF-kB signaling

项目摘要/摘要 核因子-kB家族的转录因子是多种生物过程的中央调节因子。 这包括像胚胎发育和细胞存活这样的基本事件，以及复杂的 先天免疫和获得性免疫系统的反应。仍然难以捉摸的是， 允许这组有限的五种蛋白质来协调截然不同的转录程序，这些程序是 这些不同的细胞功能所需的。了解依赖于核因子-kB的转录的细节， 然而，对于努力实现有针对性的治疗干预来说，至关重要的是 病理性核因子-kB的激活，如脓毒症、类风湿性关节炎和癌症。 微调核因子-kB活性的因素之一是核因子-kB的异构体b抑制物(IKB-b)，它已经被认为是 显示出耐人寻味的双重作用，既是核因子-kB的常规抑制物，也是非典型的共激活物。 依赖转录。在未受刺激的细胞中，IKB-b将核因子-kB二聚体隔离在细胞质中，因此 阻止转录激活，而在刺激时，IKB-b的核形式增强了转录 依赖于核因子-kB的基因的一个子集。因此，缺乏IKB-b的巨噬细胞产生的量明显减少。 暴露在激活刺激下的细胞因子TNF-a的水平，而细胞因子IL-6的水平 在很大程度上没有受到影响。 本项目的目标是全面了解IKB-b作为核因子-kB的选择性共激活剂的作用 激活。这将通过严格描述作为IKB-b功能基础的机制来实现 在生化和分子水平上。此外，IKB-b共激活子功能的充分发挥及其作用 将使用包括rna-seq和芯片在内的尖端基因组学技术来探索全球转录。 序列号。然后，这些数据集将被整合，以创建IKB-b功能的整体模型。最后，真正的 IKB-b的生理相关性将在体内用急性和慢性小鼠模型来确定。 炎症，以及细菌感染。

PROJECT SUMMARY/ABSTRACT The transcription factors of the NF-kB family are central regulators of a wide variety of biological processes. This includes events as fundamental as embryonic development and cellular survival as well as the intricate responses of the innate and adaptive immune system. What has remained elusive are the mechanisms that allow this limited set of five proteins to orchestrate the radically different transcriptional programs which are required for these disparate cellular functions. Understanding the details of NF-kB-dependent transcription, however, is of paramount importance for efforts to achieve targeted therapeutic intervention in cases of pathological NF-kB activation, such as sepsis, rheumatoid arthritis and cancer. One of the factors that fine-tune NF-kB activation is the inhibitor of NF-kB, isoform b (IkB-b), which has been shown to serve an intriguing dual role as a conventional inhibitor, and atypical co-activator, of NF-kB- dependent transcription. In unstimulated cells, IkB-b sequesters NF-kB dimers in the cytoplasm and thus prevents transcriptional activation, whereas upon stimulation a nuclear form of IkB-b enhances transcription of a subset of NF-kB-dependent genes. Consequently, IkB-b-deficient macrophages produce starkly reduced levels of the cytokine TNF-a following exposure to an activating stimulus, whereas levels of the cytokine IL-6 are largely unaffected. The goal of this project is to comprehensively understand the role of IkB-b as a selective co-activator of NF-kB activation. This will be accomplished by rigorously characterizing the mechanism that underlies IkB-b function on a biochemical and molecular level. Furthermore, the full extent of IkB-b co-activator function and its effect on global transcription will be probed using cutting-edge genomics techniques, including RNA-seq and ChIP- seq. These data sets will then be integrated to create a holistic model of IkB-b function. Finally, the true physiological relevance of IkB-b will be determined in vivo with mouse models of acute and chronic inflammation, as well as bacterial infection.