Architectural Basis of Leptin Transmembrane Signaling

瘦素跨膜信号传导的结构基础

• 批准号: 9486433
• 负责人: Georgios Skiniotis
• 金额: $ 10.63万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9486433
• 关键词: Address; Adipocytes; Anatomy; Architecture; Binding; Binding Sites; Body Weight; Brain; Cell Culture Techniques; Cell Nucleus; Cell Surface Receptors; Characteristics; Classification; Complex; Consumption; Cryoelectron Microscopy; Crystallization; Cytokine Receptors; Data; Defect; Diabetes Mellitus; Docking; Electron Microscopy; Energy Metabolism; Health; Heart Diseases; Homeostasis; Homology Modeling; Hormones; Human; Hyperglycemia; Hyperlipidemia; Hypothalamic structure; In Vitro; Insecta; Intervention; JAK1 gene; JAK2 gene; Janus kinase 2; Knowledge; Length; Leptin; Ligand Binding; Ligands; Lobe; Mammals; Membrane; Metabolic Diseases; Methods; Modeling; Molecular; Molecular Conformation; Monitor; Morbid Obesity; Neurosecretory Systems; Obesity; Osteogenesis; Pathology; Pharmacologic Substance; Phosphorylation; Phosphotransferases; Physiological; Proteins; Receptor Activation; Receptor Signaling; Regulation; Reproduction; Role; STAT3 gene; Signal Transduction; Structure; System; Techniques; Therapeutic; Tissues; Wound Healing; X-Ray Crystallography; base; density; design; energy balance; extracellular; flexibility; improved; insight; insulin sensitivity; interest; leptin receptor; mutant; particle; public health relevance; receptor; reconstitution; reconstruction; reduced food intake; response; stoichiometry; tool

DESCRIPTION (provided by applicant): Leptin (L) and its receptor (L-R) are key players in the regulation of energy homeostasis and body weight. Complex formation between leptin and the extracellular portion of L-R results in the activation of Janus kinase 2 (JAK2) that is constitutively bound on the intracellular regions of the receptor. Leptin-instigated JAK2 signaling in hypothalamic nuclei reduces food intake and stimulates energy expenditure, while functional defects in either leptin or L-R result in morbid obesity, hyperglycemia, decreased insulin sensitivity, and hyperlipidemia. Despite the crucial impact of the leptin system on body weight and other physiological responses, little is known about the structure of the L/L-R complex and its association with JAK2. One of the reasons for this lack of insight is that both L-R and JAK2 have a relatively long and flexible multi-domain arrangement that has proved to be very challenging for both large-scale purification and implementation of X-ray crystallography. The present proposal aims to overcome these limitations in addressing the architectural prerequisites of L-R signaling by applying single- particle cryo-electron microscopy (cryo-EM) to characterize the holo-complex of full-length L/L-R and JAK2. Single-particle EM has emerged as a very powerful tool for the characterization of dynamic protein assemblies in relatively small concentrations and without the need for crystallization. We anticipate that the application of single-particle EM techniques on this system will reveal the architecture of the L/L-R assembly and JAK2 independently, and in complex. Given the underlying importance of this membrane-localized signaling complex in obesity, energy metabolism, and heart disease, the structural results obtained will be of very broad biomedical interest. Considering the current lack of structural information on any receptor/JAK complex, our studies will provide the general architectural framework for understanding how extracellular ligand binding on cytokine receptors results in intracellular JAK activation.

描述（由申请人提供）：瘦素（L）及其受体（L-R）是调节能量稳态和体重的关键角色。瘦素和 L-R 细胞外部分之间形成复合物，导致 Janus 激酶 2 (JAK2) 激活，Janus 激酶 2 持续结合在受体的细胞内区域。下丘脑核中瘦素诱导的 JAK2 信号传导会减少食物摄入并刺激能量消耗，而瘦素或 L-R 的功能缺陷会导致病态肥胖、高血糖、胰岛素敏感性降低和高脂血症。尽管瘦素系统对体重和其他生理反应具有至关重要的影响，但人们对 L/L-R 复合物的结构及其与 JAK2 的关联知之甚少。缺乏洞察力的原因之一是L-R和JAK2都具有相对较长且灵活的多域排列，事实证明这对于大规模纯化和X射线晶体学的实施都非常具有挑战性。本提案旨在通过应用单粒子冷冻电子显微镜 (cryo-EM) 来表征全长 L/L-R 和 JAK2 的全息复合物，从而克服这些限制，解决 L-R 信号传导的架构先决条件。单颗粒电镜已成为一种非常强大的工具，可用于表征相对较小浓度的动态蛋白质组装体，且无需结晶。我们预计单粒子 EM 技术在该系统上的应用将独立且复杂地揭示 L/L-R 组件和 JAK2 的架构。鉴于这种膜定位信号复合物在肥胖、能量代谢和心脏病中的潜在重要性，所获得的结构结果将具有非常广泛的生物医学意义。考虑到目前缺乏任何受体/JAK 复合物的结构信息，我们的研究将为理解细胞外配体与细胞因子受体的结合如何导致细胞内 JAK 激活提供总体架构框架。

项目成果

Conformational Plasticity in the Transsynaptic Neurexin-Cerebellin-Glutamate Receptor Adhesion Complex.

• DOI: 10.1016/j.str.2016.11.004
• 发表时间: 2016-12-06
• 期刊: Structure (London, England : 1993)
• 作者: Cheng S;Seven AB;Wang J;Skiniotis G;Özkan E
• 通讯作者: Özkan E

2.8-Å Cryo-EM Structure of the Large Ribosomal Subunit from the Eukaryotic Parasite Leishmania.

• DOI: 10.1016/j.celrep.2016.06.014
• 发表时间: 2016-07-12
• 期刊: Cell reports
• 影响因子: 8.8
• 作者: Shalev-Benami M;Zhang Y;Matzov D;Halfon Y;Zackay A;Rozenberg H;Zimmerman E;Bashan A;Jaffe CL;Yonath A;Skiniotis G
• 通讯作者: Skiniotis G

Atomic resolution snapshot of Leishmania ribosome inhibition by the aminoglycoside paromomycin.

• DOI: 10.1038/s41467-017-01664-4
• 发表时间: 2017-11-17
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Shalev-Benami M;Zhang Y;Rozenberg H;Nobe Y;Taoka M;Matzov D;Zimmerman E;Bashan A;Isobe T;Jaffe CL;Yonath A;Skiniotis G
• 通讯作者: Skiniotis G