Suppressing Inflammation by Blocking IKK Oligomer

通过阻断 IKK 寡聚物抑制炎症

• 批准号: 10446098
• 负责人: GOURISANKAR GHOSH
• 金额: $ 52.93万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-15 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10446098
• 关键词: Affect; Architecture; Arthritis; Autoimmune; Autoimmunity; Binding; Biophysics; Black race; Cartoons; Catalytic Domain; Cells; Chemicals; Collagen Arthritis; Complex; Coupled; Defect; Disease; Event; Failure; Goals; Heart; IkappaB kinase; In Vitro; Industrialization; Infection; Inflammation; Inflammatory; Light; Link; Malignant Neoplasms; Modeling; Molecular Conformation; Molecular Weight; Mutation; NF-kappa B; NFKB Signaling Pathway; Pathogenicity; Peptides; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Play; Point Mutation; Polyubiquitin; Predisposition; Process; Protein Kinase; Regulation; Research Personnel; Role; Scaffolding Protein; Serine; Signal Pathway; Signal Transduction; Site; Specificity; Stimulus; Syndrome; Testing; Therapeutic; Transcriptional Activation; Ubiquitin; Zinc Fingers; adaptive immune response; base; dimer; drug development; efficacy testing; experimental study; extracellular; fighting; in vivo; inhibitor; intermolecular interaction; monomer; mouse model; mutant; novel strategies; potency testing; protein complex; protein protein interaction; receptor; response; scaffold; systemic inflammatory response; transcription factor

Uncontrolled activation of the IkappaB kinase (IKK), the key cellular regulator of NF-­κB, causes a variety of disorders, including susceptibility to pathogenic infection, autoimmunity, inflammation-­induced malignancies, and inflammatory syndromes. However, targeting the IKK-­NF-­kB signaling pathway has not yielded any new strategies for fighting inflammatory illnesses. The lack of understanding of how IKK becomes activated in response to various stimuli is the fundamental reason for our failure to exploit this unambiguous target. The IKK complex is made up of three subunits, catalytic IKK1 (also known as IKKa) and IKK2/b kinases, which form a heterodimer, and the dimeric scaffolding protein NEMO (NF-­κB Essential Modulator), which is stably bound to the heterodimer. In vitro and in cells, this fundamental tetrameric unit of the IKK complex (IKK1:IKK2:NEMO2), emerges as significantly higher molecular weight multimers. The catalytic activation of IKK2, referred to as canonical signaling, requires linear (M1-­linked), K63-­linked, or mixed poly-­ubiquitin chains (Ub-­chain) that engage noncovalently with the NEMO subunits. The mechanism by which this binding information is transferred from NEMO:Ub-­chain interaction to yield IKK2 subunit phosphorylation and subsequent activation of IKK is unknown. We hypothesize that multimerization via dimer-­dimer interaction is required for IKK2 activation and that the tetramer interface stabilizes the native IKK complex, allowing NEMO to undergo conformational changes upon binding to the Ub-­chain. The kinase domain of the IKK2 subunit is activated as a result of structural alterations in NEMO. Disease-­causing NEMO mutations or mutations at the tetramer interface do not support the assembly and Ub-­chain-­dependent NEMO conformational changes required for IKK activation. In support of our hypothesis, we have already shown that a short peptide segment derived from NEMO interacts with IKK2 in a signal-­dependent manner and that IKK multimerization requires short homologous peptide segments within IKK1 and IKK2. Under this proposal, we will achieve the following specific aims: AIM 1. We will characterize the dimer-­dimer interface which is required for IKK multimerization. We will use disease-­causing NEMO mutants and IKK multimerization-­defective mutants to test how the structural plasticity of NEMO is linked to IKK2 activation. AIM 2. We will determine if the IKK1-­ and IKK2-­derived peptides disrupt dimer-­dimer interaction and IKK2 activation in cells and in vivo. We will test if the IKK-­derived peptides independently and in combination with the NEMO-­derived peptide can ameliorate systemic inflammation and collagen-­induced arthritis in mouse models.

作为核因子-κB的关键细胞调节因子，IkappaB激酶(IKK)的不受控制的激活会导致多种疾病，包括对病原性感染、自身免疫、炎症诱导的恶性肿瘤和炎症综合征的易感性。然而，针对ikk-nf-kB信号通路并没有产生任何抗击炎症性疾病的新策略。对IKK如何在各种刺激下被激活缺乏了解是我们未能利用这一明确目标的根本原因。KIKK 复合体由催化IKK1(也称为IKKA)和IKK2/b激酶三个亚基组成，它们形成一个异二聚体，以及稳定结合到异二聚体上的二聚体支架蛋白NEMO(NF-κB Essential调制器)。在体外和细胞中，IKK复合体(IKK1：IKK2：NEMO2)的这个基本四聚体单位以明显更高的相对分子质量多聚体出现。IKK2的催化激活，被称为正则信号，需要线性(M1连接的)、K63连接的或混合的多泛素链(Ub链) 以非共价方式与NEMO亚基结合。这种结合信息是如何从NEMO：UB链相互作用转移到产生IKK2亚单位磷酸化并随后激活IKK的机制尚不清楚。我们假设IKK2的激活需要通过二聚体-二聚体相互作用的多聚体，并且 四聚体界面稳定了天然的IKK复合体，使Nemo在与Ub-链结合时经历了构象变化。由于NEMO的结构变化，IKK2亚单位的激活域被激活。致病的Nemo突变或四聚体界面的突变不支持IKK激活所需的组装和Ub链依赖的Nemo构象变化。为了支持我们的假设，我们已经证明了来自NEMO的一个短肽片段与IKK2在 这是一种信号依赖的方式，并且IKK的多聚体需要IKK1和IKK2内的较短的同源多肽片段。根据这一提议，我们将实现以下具体目标：目标1.我们将表征IKK多聚体所需的二聚体-二聚体界面。我们将使用致病Nemo突变体和IKK多聚体缺陷突变体来测试Nemo的结构可塑性如何与IKK2激活有关。 目的2.我们将确定IKK1和IKK2衍生的多肽是否破坏细胞和体内的二聚体-二聚体相互作用和IKK2的激活。我们将测试IKK衍生肽是否独立，并与Nemo衍生肽联合使用，是否可以改善小鼠模型的全身炎症和胶原蛋白诱导的关节炎。