IKK:Biophysical basis of dynamic regulation

IKK：动态调节的生物物理基础

• 批准号: 8072633
• 负责人: GOURISANKAR GHOSH
• 金额: $ 53.88万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8072633
• 关键词: Accounting; Adverse effects; Affect; Analytical Centrifugation; Architecture; Arthritis; Atherosclerosis; Binding; Binding Sites; Biochemical; Biochemical Reaction; Biochemistry; Biological Assay; Biophysics; Catalytic Domain; Cell Line; Cell Surface Receptors; Cells; Characteristics; Chronic; Chronic Disease; Complex; Computer Simulation; Coupled; Crystallography; Development; Disease; Dissociation; Dose; Drug Delivery Systems; Effectiveness; Enzymes; Equation; Estimation Techniques; Family; Feedback; Genes; Genetic; Goals; Half-Life; Heat-Shock Proteins 90; Human Pathology; IkappaB kinase; Immune; Immune response; In Vitro; Inflammatory; Inflammatory Response; Interleukin-1; Intervention; Kinetics; Lesion; Libraries; Malignant Epithelial Cell; Malignant Neoplasms; Maps; Mass Spectrum Analysis; Measures; Mediating; Methodology; Modeling; Molecular; Molecular Chaperones; Monitor; Multienzyme Complexes; NF-kappa B; Natural regeneration; Neoplasm Metastasis; Nucleotides; Outcome; Pathogenesis; Pathology; Pathway interactions; Peptide Hydrolases; Pharmaceutical Preparations; Pharmacological Treatment; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Physiology; Play; Protein Dephosphorylation; Protein Kinase; Protein Phosphatase 2A Regulatory Subunit PR53; Proteins; Reaction; Receptor Cell; Receptor Down-Regulation; Recycling; Regulation; Reporting; Rest; Role; Scaffolding Protein; Signal Transduction; Signaling Protein; Specificity; Squamous cell carcinoma; Stimulus; Stream; Structure; Structure-Activity Relationship; Study models; TNF gene; Testing; Therapeutic; Therapeutic Intervention; Tumor Necrosis Factor Receptor; Work; autocrine; base; cancer cell; cancer type; cell type; crosslink; cytokine; design; high throughput screening; immune activation; in vivo; inhibitor/antagonist; mathematical model; mutant; novel; paracrine; public health relevance; reaction rate; receptor; reconstitution; research study; response; self assembly; simulation; small molecule; src-Family Kinases; text searching; transcription factor; ubiquitin ligase; upstream kinase

DESCRIPTION (provided by applicant): IKK is the major signaling hub for inflammatory and innate immune responses. It is an enzyme complex that receives signals from a large number of cellular receptors regulates that activity of the NF-kB family of transcription factors. Misregulation of IKK is associated with many chronic diseases, such as chronic inflammatory pathologies (arthritis, atherosclerosis, etc) and many different types of cancer. Genetic evidence strongly supports IKK's critical and central role in many functions in physiology and pathology, but its potential as a drug target has not been realized. Mechanistic and biophysical studies have been lacking, and we have neither a kinetic understanding of IKK regulation nor structural information. However, what is clear is that IKK mediates signaling specificity by tight dynamic control that is stimulus-specific and induces the expression of specific sets of genes. Recent studies have reported on a tightly coupled activation and inactivation mechanism that can only be described by a multi-state activation-inactivation cycle that involves the function of several enzymes with different functions, such as ubiquitin ligases, kinases, phosphatases, and foldases. Through regulation of these activities, we hypothesize that the IKK cycle is driven in a stimulus- and cell type-specific manner, and that understanding the kinetic relationships will reveal opportunities for rationally targeted pharmacological intervention that discriminate between disease associated misregulation and stimulus-responsive regulation in healthy cells. In this proposal, we will construct a mathematical model of the IKK cycle to explore the dynamic regulation of IKK activity. We will then focus biochemical and biophysical studies on specific control mechanisms. In particular, we test the roles of IKK oligomerization, conformational changes, and upstream kinases in IKK activation and inhibition of IKK. Computational simulations will guide genetic and pharmacological manipulation of IKK dynamics. Finally, we will focus our study on how TNF and IL-1 produce differential dynamic control of IKK; how differential dose response and temporal control determine the efficacy of cytokine traps. PUBLIC HEALTH RELEVANCE: The IkappaB kinase (IKK) complex is large protein kinase that specifically receives signals from cell surface receptors and transmits the signal to downstream effector transcription factor NF-kB. IKK must remain at a low activity state under resting state of the cell and transits into a high activity state upon receiving signals. Any alteration of this tight regulatory mode of IKK results to abnormal cellular outcomes including inflammatory diseases and cancer. The precise mechanism of how IKK-intrinsic and extrinsic cellular mechanisms control IKK activity is poorly understood. This proposal will integrate diverse methodologies that include mathematical modeling, biophysics, biochemistry and genetics to probe IKK regulation.

描述（由申请人提供）：IKK是炎症和先天免疫反应的主要信号中枢。它是一种酶复合物，接收来自大量细胞受体的信号，调节NF-kB转录因子家族的活性。IKK的失调与许多慢性疾病有关，如慢性炎症病理（关节炎、动脉粥样硬化等）和许多不同类型的癌症。遗传证据强烈支持IKK在许多生理和病理功能中的关键和核心作用，但其作为药物靶点的潜力尚未实现。机制和生物物理研究一直缺乏，我们既没有对IKK调控的动力学理解，也没有结构信息。然而，明确的是，IKK通过刺激特异性的严格动态控制介导信号特异性，并诱导特定基因组的表达。最近的研究报道了一种紧密耦合的激活和失活机制，这种机制只能通过一个多状态的激活-失活周期来描述，该周期涉及几种具有不同功能的酶的功能，如泛素连接酶、激酶、磷酸酶和折叠酶。通过对这些活动的调节，我们假设IKK周期是以刺激和细胞类型特异性的方式驱动的，并且了解动力学关系将揭示合理靶向药物干预的机会，从而区分健康细胞中疾病相关的失调和刺激反应性调节。在本文中，我们将构建IKK周期的数学模型来探索IKK活性的动态调控。然后，我们将重点研究具体的控制机制的生化和生物物理。特别是，我们测试了IKK寡聚化、构象变化和上游激酶在IKK激活和IKK抑制中的作用。计算模拟将指导IKK动力学的遗传和药理学操作。最后，我们将重点研究TNF和IL-1如何产生IKK的差异动态控制；不同剂量反应和时间控制如何决定细胞因子陷阱的效果。