Solution structure and dynamics of polyubiquitin chains

多聚泛素链的溶液结构和动力学

• 批准号: 10224823
• 负责人: DAVID FUSHMAN
• 金额: $ 32.36万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10224823
• 关键词: 26S proteasome; Address; Affinity; Amaze; Binding; Binding Proteins; Biological Process; Cell Cycle; Cell physiology; Cells; Chemicals; Complex; Computer Models; Computing Methodologies; Cyclic Peptides; Data; Defect; Development; Disease; Drug Design; Event; Head; Immune; Immune response; Immunity; Inflammation; Inflammatory; Knowledge; Length; Link; Lysine; Malignant - descriptor; Malignant Neoplasms; Measurement; Mediating; Modernization; Molecular; Molecular Conformation; Muscular Atrophy; Neurodegenerative Disorders; Neutrons; Outcome; Pathway interactions; Physiological; Polyubiquitin; Polyubiquitination; Property; Proteins; Regulation; Research; Roentgen Rays; Signal Pathway; Signal Transduction; Signaling Molecule; Specificity; Structure; Structure-Activity Relationship; System; Tail; Testing; Therapeutic; Transcriptional Activation; Ubiquitin; Work; antigen processing; design; developmental disease; ds-DNA; flexibility; improved; inhibitor/antagonist; insight; molecular marker; monomer; multicatalytic endopeptidase complex; multiple data types; novel; preference; protein degradation; protein transport; receptor; repaired; response; therapeutic development; three dimensional structure

Project Summary This work will characterize the solution structure, dynamics, and interactions of polyubiquitin (polyUb) chains, which function as signaling molecules in the regulation of a host of cellular processes, ranging from progression through the cell cycle, to transcriptional activation, antigen processing and vesicular trafficking of proteins. Conjugation of substrates to polyUb chains of different linkage types commits the target protein to distinct fates in the cell. In particular, Lys48-linked polyUb acts as a universal signal in the ubiquitin- proteasome proteolytic pathway, the principal regulatory mechanism for the turnover of short-lived proteins that influences a variety of vital cellular events. Understanding how polyUb chains are recognized by the 26S proteasome and other downstream effector molecules is central to our understanding of the mechanisms of regulation. Despite an increasing wealth of information on the cellular processes regulated by polyubiquitination and the identification of numerous ubiquitin-binding proteins that tie the polyUb signal to downstream events, the molecular basis of diversity in ubiquitin-mediated signaling remains unclear. The mechanisms underlying the ability of different polyUb chains to signal for distinct outcomes remain to be elucidated before the origin of specificity in polyUb signaling is understood. Obtaining such information is absolutely necessary in order to develop a molecular understanding of how different chains are able to act as specific signals. The objective of the proposed work is to characterize the structure and recognition properties of various types of polyUb chains, in order to understand at a molecular level the structural basis for ubiquitin's ability to serve as a versatile yet specific cellular signal. These studies will focus on the so-called non-canonical ubiquitin chains: linked via lysines other than Lys48 or Lys63 (e.g., Lys6, Lys27) and chains containing heterogeneous linkages (e.g., Lys11 & Lys48), branched and unbranched. We will also determine the conformations of the canonical, Lys48-linked tetraUb chains in solution in order to gain insights into the mechanisms of their recognition by cellular receptors. Finally, these studies will characterize the interactions and determine the structures of polyUb complexes with the recently designed cyclic peptides that bind polyUb with high affinity and specificity in order to facilitate further development and optimization of this entirely novel class of modulators and potential therapeutics for ubiquitin-mediated signaling pathways. We will use modern NMR approaches in combination with small-angle X-ray and neutron scattering (SAXS, SANS) to determine the three-dimensional structures and conformational ensembles of polyUb chains in solution and to characterize their binding preferences and complexes with receptors.

项目摘要 这项工作将表征多泛素（polyub）链的溶液结构，动力学和相互作用， 在调节大量细胞过程中，哪个起着信号分子的作用，从 通过细胞周期发展，转录激活，抗原加工和囊泡运输 蛋白质。底物与不同连锁类型的多工链的结合将目标蛋白提交给 细胞中的不同命运。特别是，lys48链接的polyub充当泛素 - 蛋白酶体蛋白水解途径，这是短寿命蛋白营业率的主要调节机制 影响各种重要的细胞事件。了解26S如何识别多元链 蛋白酶体和其他下游效应分子对于我们对机制的理解至关重要 规定。尽管越来越多的有关细胞过程的信息 多泛素化和鉴定多种泛素结合蛋白将polyub信号绑定到 下游事件，泛素介导的信号传导中多样性的分子基础尚不清楚。这 不同多元链发信号以确保不同结果的能力的机制仍然是 在polyub信号传导中的特异性起源之前阐明。获取此类信息是 绝对必要以对分子了解不同的链如何充当 具体信号。拟议工作的目的是表征结构和识别特性 为了在分子水平上理解泛素的结构基础， 能够充当多功能但特定的细胞信号。这些研究将重点放在所谓的非规范上 泛素链：除lys48或lys63（例如Lys6，Lys27）以外的赖氨酸链接和包含的链条 异质链接（例如Lys11和Lys48），分支和无分支。我们还将确定 溶液中规范，LYS48连接的四链​​链的构象，以便深入了解 通过细胞受体识别的机制。最后，这些研究将表征相互作用 并确定与最近设计的循环肽结合polyub的结构 具有高亲和力和特异性，以促进这种完全新颖的发展和优化 用于泛素介导的信号通路的调节剂和潜在的治疗剂。我们将使用现代 NMR方法与小角度X射线和中子散射（SAX，SANS）结合使用以确定 溶液中polyub链的三维结构和构象合团 表征其结合偏好和与受体的复合物。