Suppressing Inflammation by Blocking IKK Oligomer

通过阻断 IKK 寡聚物抑制炎症

• 批准号: 10573218
• 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/10573218
• 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; Innate Immune Response; Light; Link; Malignant Neoplasms; Modeling; Molecular Conformation; Molecular Weight; Mutation; NF-kappa B; Pathogenicity; Peptides; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Play; Point Mutation; 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; 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.

IkappaB激酶（IKK）（NF-κ B B的关键细胞调节剂）的不受控制的活化导致多种病症，包括对病原性感染、自身免疫、炎症诱导的恶性肿瘤和炎性综合征的易感性。然而，针对IKK-NF-κ B信号通路并没有产生任何对抗炎症性疾病的新策略。缺乏对IKK如何响应各种刺激而被激活的理解是我们未能利用这一明确目标的根本原因。IKK 复合物由三个亚基组成，即形成异二聚体的催化性IKK 1（也称为IKK κ B）和IKK 2/B激酶，以及稳定结合异二聚体的二聚体支架蛋白NEMO（NF-κ B B必需调节剂）。在体外和细胞中，IKK复合物的这种基本四聚体单元（IKK 1：IKK 2：NEMO 2）以明显更高分子量的多聚体出现。IKK 2的催化活化，称为典型信号传导，需要线性（M1-β连接的）、K63-β连接的或混合的多聚-β泛素链（Ub-β链）， 与NEMO亚基非共价结合。这种结合信息从NEMO：Ub-β链相互作用转移到IKK 2亚基磷酸化和随后IKK活化的机制尚不清楚。我们假设IKK 2激活需要通过二聚体-β-二聚体相互作用的多聚化， 四聚体界面稳定了天然IKK复合物，使NEMO在与Ub-IKK链结合时发生构象变化。IKK 2亚基的激酶结构域由于NEMO的结构改变而被激活。引起疾病的NEMO突变或四聚体界面处的突变不支持IKK激活所需的组装和Ub-β链依赖性NEMO构象变化.为了支持我们的假设，我们已经证明了来自NEMO的短肽段与IKK 2相互作用， IKK多聚化需要IKK 1和IKK 2内的短同源肽段。根据这一建议，我们将实现以下具体目标：目标1。我们将描述IKK多聚化所需的二聚体-β-二聚体界面。我们将使用引起疾病的NEMO突变体和IKK多聚化缺陷突变体来测试NEMO的结构可塑性如何与IKK 2激活相关联。 AIM 2.我们将确定IKK 1-κ B和IKK 2-κ B衍生肽是否破坏二聚体-κ B二聚体相互作用和细胞内和体内IKK 2活化。我们将在小鼠模型中测试IKK-β衍生肽单独和与NEMO-β衍生肽组合是否可以改善全身性炎症和胶原蛋白-β诱导的关节炎.