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.

IkappaB 激酶 (IKK) 是 NF-κB 的关键细胞调节因子，其不受控制的激活会导致多种疾病，包括对病原体感染的易感性、自身免疫、炎症诱发的恶性肿瘤和炎症综合征。然而，针对 IKK-NF-kB 信号通路尚未产生任何对抗炎症性疾病的新策略。对 IKK 如何响应各种刺激而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。 IKK 复合物由三个亚基组成，催化 IKK1（也称为 IKKa）和 IKK2/b 激酶（形成异二聚体）和二聚体支架蛋白 NEMO（NF-κB 必需调节剂）（稳定结合到异二聚体）。在体外和细胞中，IKK 复合物的这一基本四聚体单位 (IKK1:IKK2:NEMO2) 表现为分子量明显更高的多聚体。 IKK2 的催化激活（称为经典信号传导）需要线性（M1 连接）、K63 连接或混合多聚泛素链（Ub 链）， 与 NEMO 亚基非共价结合。这种结合信息从 NEMO:Ub 链相互作用转移到产生 IKK2 亚基磷酸化和随后 IKK 激活的机制尚不清楚。我们假设 IKK2 激活需要通过二聚体-二聚体相互作用进行多聚化，并且 四聚体界面稳定了天然 IKK 复合物，使 NEMO 在与 Ub 链结合后发生构象变化。 IKK2 亚基的激酶结构域因 NEMO 中的结构改变而被激活。引起疾病的 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 链依赖性 NEMO 构象变化。为了支持我们的假设，我们已经证明源自 NEMO 的短肽片段与 IKK2 相互作用 信号依赖性方式，并且 IKK 多聚化需要 IKK1 和 IKK2 内的短同源肽片段。根据该提案，我们将实现以下具体目标： AIM 1.我们将表征 IKK 多聚化所需的二聚体-二聚体界面。我们将使用致病的 NEMO 突变体和 IKK 多聚化缺陷突变体来测试 NEMO 的结构可塑性与 IKK2 激活之间的关系。 目标 2. 我们将确定 IKK1 和 IKK2 衍生肽是否会破坏细胞和体内二聚体-二聚体相互作用以及 IKK2 激活。我们将测试 IKK 衍生肽单独以及与 NEMO 衍生肽组合是否可以改善小鼠模型中的全身炎症和胶原诱导的关节炎。