Structural Biology of the Ubiquitin Conjugation System

泛素结合系统的结构生物学

• 批准号: 10224223
• 负责人: Shaun Olsen
• 金额: $ 31.55万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-22 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10224223
• 关键词: Active Sites; Address; Architecture; BARD1 gene; BRCA1 gene; Biochemical; Biological; Biological Assay; Biology; Biophysics; Cardiovascular Diseases; Catalysis; Cell Cycle Regulation; Cell physiology; Cells; Cellular biology; Complex; Crystallization; Cysteine; DNA Repair; Data; Development; Disease; Endoplasmic Reticulum Degradation Pathway; Enzymes; Eukaryotic Cell; Exhibits; FDA approved; Family; Goals; Hand; Health; Human; Human Activities; Human Pathology; Immune System Diseases; Immunity; In Vitro; Link; Lysine; Maintenance; Malignant Neoplasms; Methionine; Methodology; Mitotic; Molecular; Multiple Myeloma; Multiprotein Complexes; N-terminal; Pathology; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Polymers; Positioning Attribute; Post-Translational Protein Processing; Process; Property; Proteins; Reaction; Regulation; Role; Secure; Signal Transduction; Specificity; Structure; Substrate Specificity; System; TRAP Complex; Techniques; Therapeutic Intervention; Time; UBD protein; UBE2G2 gene; Ubiquitin; Ubiquitin Like Proteins; Ubiquitination; Work; X-Ray Crystallography; Yeasts; base; crosslink; experimental study; functional outcomes; human disease; intermolecular interaction; molecular recognition; nervous system disorder; neuron development; novel; recruit; single molecule; small molecule therapeutics; structural biology; targeted treatment; thioester; ubiquitin-protein ligase

Project Summary Posttranslational modification of proteins by ubiquitin (Ub) is a regulatory mechanism that controls nearly all aspects eukaryotic cell biology. Ubiquitination alters properties of target proteins such as stability, subcellular localization, intermolecular interactions, and activity and thereby regulates processes such as cell cycle control, DNA repair, signal transduction, and immunity. The relevance of Ub signaling to human health is underscored by the fact that its dysregulation is implicated in pathologies such as cancer, neurological disorders, cardiovascular disease, and immune disorders and that it is a validated target for therapeutic intervention in cancer with FDA-approved medications extending the lives of multiple myeloma patients. Ub signaling requires the sequential interactions and activities of three enzymes, E1, E2, and E3, which act in tandem to conjugate Ub to target proteins. Humans harbor two Ub E1s, Uba1 and Uba6, that catalyze Ub activation and thioester transfer to distinct repertoires of tens of E2s. While Uba1 is fully dedicated to Ub activation, Uba6 is highly unusual in that it is also capable of activating FAT10 (a Ub-like protein involved in mitotic progression and immunity), and subsequently transferring it to a highly Uba6-specific E2, UBE2Z. Maintenance of the integrity of Ub signaling is essential, yet mechanisms underlying Uba6 promiscuity for Ub and FAT10, as well as the molecular rules governing specificity/promiscuity in E1/E2 interactions remain poorly understood. After E1-E2 thioester transfer, E2~Ub intermediates interact with distinct repertoires of hundreds of E3 ligases grouped into three families that catalyze ubiquitination of target proteins as a single molecule or as polymeric chains linked together by specific lysine residues on Ub. Because it is a major determinant of the functional outcome of ubiquitination, control of the type of polyUb chains assembled on substrate proteins is essential and for reactions catalyzed by RING E3s, polyUb chain specificity is largely determined by the E2 with which they function. Despite this fundamental importance, the molecular mechanisms governing specificity in catalysis of most polyUb linkage types remain unknown. Through use of structural, biochemical/biophysical, and cell-based approaches, this proposal aims to discover: 1) the structural basis for substrate recognition and catalytic activities of human Ub E1 enzymes 2) the catalytic mechanism of E1-E2 thioester transfer and molecular rules governing specificity/promiscuity in Ub E1/E2 interactions, and 3) mechanisms by which specific types of polyUb chains are catalyzed by E2/RING E3 pairs. Ub signaling is a target for therapeutic intervention in cancer and other human pathologies and the deeper understanding of how E1, E2, and E3 work together to control essential cellular processes that will result from the proposed studies could provide a platform for the development of novel small molecule therapeutics.

项目概要 泛素 (Ub) 对蛋白质的翻译后修饰是一种调控机制，几乎控制所有蛋白质 真核细胞生物学方面。泛素化改变靶蛋白的特性，例如稳定性、亚细胞性 定位、分子间相互作用和活性，从而调节细胞周期等过程 控制、DNA 修复、信号转导和免疫。 Ub 信号传导与人类健康的相关性是 事实上，它的失调与癌症、神经系统疾病等疾病有关。 疾病、心血管疾病和免疫疾病，并且它是治疗的有效靶点 使用 FDA 批准的药物干预癌症，延长多发性骨髓瘤患者的生命。 Ub 信号传导需要三种酶 E1、E2 和 E3 的连续相互作用和活性，它们在 串联将 Ub 与靶蛋白结合。人类拥有两个 Ub E1，Uba1 和 Uba6，它们催化 Ub 激活和硫酯转移到数十个 E2 的不同库。而Uba1完全致力于Ub Uba6 非常不寻常，因为它还能够激活 FAT10（一种 Ub 样蛋白，参与 有丝分裂进展和免疫），然后将其转移到高度 Uba6 特异性的 E2，UBE2Z。 维持 Ub 信号完整性至关重要，但 Uba6 与 Ub 混杂的潜在机制 和 FAT10，以及控制 E1/E2 相互作用中特异性/混杂性的分子规则仍然很差 明白了。 E1-E2 硫酯转移后，E2~Ub 中间体与数百种不同的相互作用 E3 连接酶分为三个家族，以单个分子或形式催化靶蛋白的泛素化 作为通过 Ub 上的特定赖氨酸残基连接在一起的聚合链。因为它是一个重要的决定因素 泛素化的功能结果，对底物蛋白上组装的多聚泛素链类型的控制是 对于 RING E3 催化的反应来说，polyUb 链的特异性很大程度上取决于 E2 它们发挥作用。尽管具有这一根本重要性，但控制的分子机制 大多数多聚泛素连接类型的催化特异性仍然未知。 通过使用结构、生物化学/生物物理和基于细胞的方法，该提案旨在发现： 1) 人 Ub E1 酶底物识别和催化活性的结构基础 2) 催化 E1-E2硫酯转移机制和控制Ub E1/E2特异性/混杂性的分子规则 相互作用，以及 3) E2/RING E3 对催化特定类型多聚泛素链的机制。 Ub 信号传导是癌症和其他人类病理学以及更深层次治疗干预的目标 了解 E1、E2 和 E3 如何协同工作来控制由以下因素产生的重要细胞过程 拟议的研究可以为开发新型小分子疗法提供平台。